WO2016108674A1 - Uplink signal transmitting method and user equipment, and uplink signal receiving method and base station - Google Patents

Abstract

The present invention provides a method and device for transmitting/receiving an uplink signal. When a user equipment of the present invention is configured by multiple cell groups and multiple pieces of uplink control information (UCI) to be transmitted by the user equipment in a sub-frame are generated, the user equipment separately transmits, to the multiple cell groups, the UCI one by one from the piece of UCI having the highest priority, and drops the pieces of UCI having lower priorities among the multiple pieces of UCI.

Description

UL signal transmission method and user equipment, UL signal reception method and base station

The present invention relates to a wireless communication system, and to a method and apparatus for transmitting or receiving an uplink signal.

Various devices and technologies, such as smartphone-to-machine communication (M2M) and smart phones and tablet PCs, which require high data transmission rates, are emerging and spread. As a result, the amount of data required to be processed in a cellular network is growing very quickly. In order to meet this rapidly increasing data processing demand, carrier aggregation technology, cognitive radio technology, etc. to efficiently use more frequency bands, and increase the data capacity transmitted within a limited frequency Multi-antenna technology, multi-base station cooperation technology, and the like are developing.

A typical wireless communication system performs data transmission / reception over one downlink (DL) band and one uplink (UL) band corresponding thereto (frequency division duplex (FDD) mode). Or a predetermined radio frame divided into an uplink time unit and a downlink time unit in a time domain, and perform data transmission / reception through uplink / downlink time units (time division duplex). (for time division duplex, TDD) mode). A base station (BS) and a user equipment (UE) transmit and receive data and / or control information scheduled in a predetermined time unit, for example, a subframe (SF). Data is transmitted and received through the data area set in the uplink / downlink subframe, and control information is transmitted and received through the control area set in the uplink / downlink subframe. To this end, various physical channels carrying radio signals are configured in uplink / downlink subframes. In contrast, the carrier aggregation technique can collect a plurality of uplink / downlink frequency blocks to use a wider frequency band and use a larger uplink / downlink bandwidth, so that a greater amount of signals can be processed simultaneously than when a single carrier is used. .

Meanwhile, the communication environment is evolving in a direction in which the density of nodes that the UE can access in the vicinity is increased. A node is a fixed point capable of transmitting / receiving a radio signal with a UE having one or more antennas. A communication system having a high density of nodes can provide higher performance communication services to the UE by cooperation between nodes.

With the introduction of a new wireless communication technology, not only the number of UEs that a base station needs to provide service in a predetermined resource area increases, but also the amount of data and control information transmitted / received by UEs that provide service It is increasing. Since the amount of radio resources available for the base station to communicate with the UE (s) is finite, the base station uses finite radio resources to transmit uplink / downlink data and / or uplink / downlink control information to / from the UE (s). There is a need for a new scheme for efficient reception / transmission.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above are apparent to those skilled in the art from the following detailed description. Can be understood.

The present invention provides an uplink signal transmission method and user equipment, an uplink signal reception method, and a base station.

When the user equipment of the present invention is configured as a plurality of cell groups, and a plurality of uplink control information (UCIs) to be transmitted in a subframe is generated by the user equipment, the user equipment has the highest priority among the plurality of UCIs. UCI (s) having a priority are transmitted to the plurality of cell groups one by one, and UCI (s) having subordinated priorities are dropped.

In an aspect of the present invention, when a user equipment configured with a plurality of cell groups transmits an uplink signal, a plurality of uplink control information configured to be transmitted in subframe n through at least one of the plurality of cell groups. receiving UCI transmission information for information (UCI); And based on the UCI transmission information, in the subframe n, transmitting a first UCI of at least the highest priority and a second UCI of a next higher priority among the plurality of UCIs. do.

In another aspect of the present invention, a user equipment including a radio frequency (RF) unit and a processor configured to control the RF unit in transmitting a UL signal by a user equipment configured with a plurality of cell groups includes: Is provided. The processor is configured to: control the RF unit to receive UCI transmission information for a plurality of uplink control information (UCI) configured to be transmitted in subframe n through at least one of the plurality of cell groups; Based on the UCI transmission information, in the subframe n, the RF unit may be controlled to transmit a first UCI of at least the highest priority and a second UCI of a next higher priority among the plurality of UCIs.

In another aspect of the present invention, when the user equipment configured with a plurality of cell groups is received by the base station, a plurality of uplink control information configured to be transmitted in subframe n through at least one of the plurality of cell groups. transmit UCI transmission information for uplink control information (UCI); And receiving, according to the UCI transmission information, in the subframe n, a first UCI of at least the highest priority and a second UCI of a next higher priority among the plurality of UCIs. do.

In still another aspect of the present invention, a base station includes a radio frequency (RF) unit and a processor configured to control the RF unit when the user equipment configured with a plurality of cell groups receives an uplink signal. A base station is provided. The processor is configured to: control the RF unit to transmit UCI transmission information for a plurality of uplink control information (UCI) configured to be transmitted in subframe n through at least one of the plurality of cell groups; Based on the UCI transmission information, in the subframe n, the RF unit may be controlled to receive a first UCI of at least the highest priority and a second UCI of a next higher priority among the plurality of UCIs.

In each aspect of the present invention, when both the first UCI and the second UCI are set in a first cell group, the first UCI is transmitted on the first cell group and the second UCI is the first cell group Can be transmitted on the second cell group.

In each aspect of the present invention, one of the first cell group and the second cell group is a primary cell group having a primary cell, and the second cell group is the primary cell group without the primary cell. It may be a secondary cell group consisting of one or more secondary cells that do not belong to.

In each aspect of the present invention, information indicating a special secondary cell for transmitting a physical uplink control channel (PUCCH) among the one or more secondary cells belonging to the primary cell group is informed to the user equipment. Can be provided.

In each aspect of the present invention, the first UCI and the second UCI may be UCI in which simultaneous transmission is not allowed on a single physical uplink channel.

In each aspect of the present invention, if there is a third UCI having a lower priority than the first UCI and the second UCI set in the first cell group or the second cell group in the subframe n, 3 UCI transmission can be dropped.

The problem solving methods are only a part of embodiments of the present invention, and various embodiments reflecting the technical features of the present invention are based on the detailed description of the present invention described below by those skilled in the art. Can be derived and understood.

According to an embodiment of the present invention, the wireless communication signal can be efficiently transmitted / received. Accordingly, the overall throughput of the wireless communication system can be high.

The effects according to the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the detailed description of the present invention. There will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide an embodiment of the present invention and together with the description, illustrate the technical idea of the present invention.

1 illustrates an example of a radio frame structure used in a wireless communication system.

2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system.

3 illustrates a downlink (DL) subframe structure used in a wireless communication system.

4 illustrates an example of an uplink (UL) subframe structure used in a wireless communication system.

5 is a diagram for describing single carrier communication and multicarrier communication.

6 illustrates states of cells in a system supporting carrier aggregation.

7 to 9 illustrate examples of physically mapping a PUCCH format to PUCCH resources.

10 illustrates a subframe configuration of a reserved resource period (RRP).

11 through 14 illustrate transmission of uplink control information (UCI) according to embodiments of the present invention.

15 is a block diagram showing the components of the transmitter 10 and the receiver 20 for carrying out the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components will be described with the same reference numerals throughout the present specification.

The techniques, devices, and systems described below can be applied to various wireless multiple access systems. Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and single carrier frequency (SC-FDMA). division multiple access (MCD) systems and multi-carrier frequency division multiple access (MC-FDMA) systems. CDMA may be implemented in a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented in radio technologies such as Global System for Mobile Communication (GSM), General Packet Radio Service (GPRS), Enhanced Data Rates for GSM Evolution (EDGE) (i.e., GERAN), and the like. OFDMA may be implemented in wireless technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE802-20, evolved-UTRA (E-UTRA), and the like. UTRA is part of Universal Mobile Telecommunication System (UMTS), and 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of E-UMTS using E-UTRA. 3GPP LTE adopts OFDMA in downlink (DL) and SC-FDMA in uplink (UL). LTE-advanced (LTE-A) is an evolution of 3GPP LTE. For convenience of explanation, hereinafter, it will be described on the assumption that the present invention is applied to 3GPP LTE / LTE-A. However, the technical features of the present invention are not limited thereto. For example, even if the following detailed description is described based on the mobile communication system corresponding to the 3GPP LTE / LTE-A system, any other mobile communication except for the matters specific to 3GPP LTE / LTE-A is described. Applicable to the system as well.

For example, in the present invention, as in the 3GPP LTE / LTE-A system, an eNB allocates a downlink / uplink time / frequency resource to a UE, and the UE receives a downlink signal according to the allocation of the eNB and transmits an uplink signal. In addition to non-contention based communication, it can be applied to contention-based communication such as WiFi. In the non-competition based communication scheme, an access point (AP) or a control node controlling the access point allocates resources for communication between a UE and the AP, whereas a competition-based communication technique connects to an AP. Communication resources are occupied through contention among multiple UEs that are willing to. A brief description of the contention-based communication technique is a type of contention-based communication technique called carrier sense multiple access (CSMA), which is a shared transmission medium in which a node or a communication device is a frequency band. probabilistic media access control (MAC) protocol that ensures that there is no other traffic on the same shared transmission medium before transmitting traffic on a shared transmission medium (also called a shared channel). protocol). In CSMA, the transmitting device determines if another transmission is in progress before attempting to send traffic to the receiving device. In other words, the transmitting device attempts to detect the presence of a carrier from another transmitting device before attempting to transmit. When the carrier is detected, the transmission device waits for transmission to be completed by another transmission device in progress before initiating its transmission. After all, CSMA is a communication technique based on the principle of "sense before transmit" or "listen before talk". Carrier Sense Multiple Access with Collision Detection (CSMA / CD) and / or Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) are used as a technique for avoiding collision between transmission devices in a contention-based communication system using CSMA. . CSMA / CD is a collision detection technique in a wired LAN environment. First, a PC or a server that wants to communicate in an Ethernet environment checks if a communication occurs on the network, and then another device If you are sending on the network, wait and send data. That is, when two or more users (eg, PCs, UEs, etc.) simultaneously carry data, collisions occur between the simultaneous transmissions. CSMA / CD monitors the collisions to allow flexible data transmission. Technique. A transmission device using CSMA / CD detects data transmission by another transmission device and adjusts its data transmission using a specific rule. CSMA / CA is a media access control protocol specified in the IEEE 802.11 standard. WLAN systems according to the IEEE 802.11 standard use a CA, that is, a collision avoidance method, without using the CSMA / CD used in the IEEE 802.3 standard. The transmitting devices always detect the carrier of the network, and when the network is empty, wait for a certain amount of time according to their location on the list and send the data. Various methods are used to prioritize and reconfigure transmission devices within a list. In a system according to some versions of the IEEE 802.11 standard, a collision may occur, in which a collision detection procedure is performed. Transmission devices using CSMA / CA use specific rules to avoid collisions between data transmissions by other transmission devices and their data transmissions.

In the present invention, the UE may be fixed or mobile, and various devices which communicate with a base station (BS) to transmit and receive user data and / or various control information belong to the same. UE (Terminal Equipment), MS (Mobile Station), MT (Mobile Terminal), UT (User Terminal), SS (Subscribe Station), wireless device, PDA (Personal Digital Assistant), wireless modem ), A handheld device, or the like. In addition, in the present invention, a BS generally refers to a fixed station communicating with the UE and / or another BS, and communicates with the UE and another BS to exchange various data and control information. The BS may be referred to in other terms such as ABS (Advanced Base Station), Node-B (NB), evolved-NodeB (NB), Base Transceiver System (BTS), Access Point, and Processing Server (PS). In the following description of the present invention, BS is collectively referred to as eNB.

In the present invention, a node refers to a fixed point capable of transmitting / receiving a radio signal by communicating with a UE. Various forms of eNBs may be used as nodes regardless of their names. For example, a node may be a BS, an NB, an eNB, a pico-cell eNB (PeNB), a home eNB (HeNB), a relay, a repeater, or the like. Also, the node may not be an eNB. For example, it may be a radio remote head (RRH), a radio remote unit (RRU). RRH, RRU, etc. generally have a power level lower than the power level of the eNB. Since RRH or RRU, RRH / RRU) is generally connected to the eNB by a dedicated line such as an optical cable, RRH / RRU and eNB are generally compared to cooperative communication by eNBs connected by a wireless line. By cooperative communication can be performed smoothly. At least one antenna is installed at one node. The antenna may mean a physical antenna or may mean an antenna port, a virtual antenna, or an antenna group. Nodes are also called points.

In the present invention, a cell refers to a certain geographic area in which one or more nodes provide communication services. Therefore, in the present invention, communication with a specific cell may mean communication with an eNB or a node that provides a communication service to the specific cell. In addition, the downlink / uplink signal of a specific cell means a downlink / uplink signal from / to an eNB or a node that provides a communication service to the specific cell. A cell that provides uplink / downlink communication service to a UE is particularly called a serving cell. In addition, the channel state / quality of a specific cell means a channel state / quality of a channel or communication link formed between an eNB or a node providing a communication service to the specific cell and a UE. In an LTE / LTE-A based system, the UE transmits a downlink channel state from a specific node to a CRS in which antenna port (s) of the specific node are transmitted on a Cell-specific Reference Signal (CRS) resource allocated to the specific node. It may be measured using the CSI-RS (s) transmitted on the (s) and / or Channel State Information Reference Signal (CSI-RS) resources. For detailed CSI-RS configuration, reference may be made to 3GPP TS 36.211 and 3GPP TS 36.331 documents.

Meanwhile, the 3GPP LTE / LTE-A system uses the concept of a cell to manage radio resources. Cells associated with radio resources are distinguished from cells in a geographic area.

A "cell" in a geographic area may be understood as coverage in which a node can provide services using a carrier, and a "cell" of radio resources is a bandwidth (frequency) that is a frequency range configured by the carrier. bandwidth, BW). Since downlink coverage, which is a range in which a node can transmit valid signals, and uplink coverage, which is a range in which a valid signal is received from a UE, depends on a carrier carrying the signal, the coverage of the node is determined by the radio resources used by the node. It is also associated with the coverage of the "cell". Thus, the term "cell" can sometimes be used to mean coverage of a service by a node, sometimes a radio resource, and sometimes a range within which a signal using the radio resource can reach a valid strength. The "cell" of radio resources is described in more detail later.

The 3GPP LTE / LTE-A standard corresponds to downlink physical channels corresponding to resource elements carrying information originating from an upper layer and resource elements used by the physical layer but not carrying information originating from an upper layer. Downlink physical signals are defined. For example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), a physical multicast channel (PMCH), a physical control format indicator channel (physical control) format indicator channel (PCFICH), physical downlink control channel (PDCCH) and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, reference signal and synchronization signal Is defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, refers to a signal of a predetermined special waveform known to the eNB and the UE. For example, a cell specific RS, UE- UE-specific RS, positioning RS (PRS), and channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE / LTE-A standard corresponds to uplink physical channels corresponding to resource elements carrying information originating from a higher layer and resource elements used by the physical layer but not carrying information originating from an upper layer. Uplink physical signals are defined. For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are the uplink physical channels. A demodulation reference signal (DMRS) for uplink control / data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

In the present invention, Physical Downlink Control CHannel (PDCCH) / Physical Control Format Indicator CHannel (PCFICH) / PHICH (Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel) are respectively DCI (Downlink Control Information) / CFI ( Means a set of time-frequency resources or a set of resource elements that carry downlink format ACK / ACK / NACK (ACKnowlegement / Negative ACK) / downlink data, and also a Physical Uplink Control CHannel (PUCCH) / Physical (PUSCH) Uplink Shared CHannel / PACH (Physical Random Access CHannel) means a set of time-frequency resources or a set of resource elements that carry uplink control information (UCI) / uplink data / random access signals, respectively. The PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH RE is allocated to the PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH. The PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH resource is referred to below: The expression that the user equipment transmits the PUCCH / PUSCH / PRACH is hereinafter referred to as uplink control information / uplink on or through PUSCH / PUCCH / PRACH, respectively. It is used in the same sense as transmitting a data / random access signal, and the expression that the eNB transmits PDCCH / PCFICH / PHICH / PDSCH is used for downlink data / control information on or through PDCCH / PCFICH / PHICH / PDSCH, respectively. It is used in the same sense as sending it.

In the following description, CRS / DMRS / CSI-RS / SRS / UE-RS is assigned or configured OFDM symbol / subcarrier / RE to CRS / DMRS / CSI-RS / SRS / UE-RS symbol / carrier / subcarrier / RE. It is called. For example, an OFDM symbol assigned or configured with a tracking RS (TRS) is called a TRS symbol, a subcarrier assigned or configured with a TRS is called a TRS subcarrier, and an RE assigned or configured with a TRS is called a TRS RE. . In addition, a subframe configured for TRS transmission is called a TRS subframe. Also, a subframe in which a broadcast signal is transmitted is called a broadcast subframe or a PBCH subframe, and a subframe in which a sync signal (for example, PSS and / or SSS) is transmitted is a sync signal subframe or a PSS / SSS subframe. It is called. An OFDM symbol / subcarrier / RE to which PSS / SSS is assigned or configured is referred to as a PSS / SSS symbol / subcarrier / RE, respectively.

In the present invention, the CRS port, the UE-RS port, the CSI-RS port, and the TRS port are an antenna port configured to transmit CRS, an antenna port configured to transmit UE-RS, and an antenna configured to transmit CSI-RS, respectively. Port, an antenna port configured to transmit TRS. Antenna ports configured to transmit CRSs may be distinguished from each other by the location of REs occupied by the CRS according to the CRS ports, and antenna ports configured to transmit UE-RSs may be UE-RS according to the UE-RS ports. The RSs may be distinguished from each other by locations of REs occupied, and antenna ports configured to transmit CSI-RSs may be distinguished from each other by locations of REs occupied by the CSI-RSs according to the CSI-RS ports. Therefore, the term CRS / UE-RS / CSI-RS / TRS port may be used as a term for a pattern of REs occupied by CRS / UE-RS / CSI-RS / TRS in a certain resource region.

1 illustrates an example of a radio frame structure used in a wireless communication system.

In particular, Figure 1 (a) shows a frame structure for frequency division duplex (FDD) used in the 3GPP LTE / LTE-A system, Figure 1 (b) is used in the 3GPP LTE / LTE-A system The frame structure for time division duplex (TDD) is shown.

Referring to FIG. 1, a radio frame used in a 3GPP LTE / LTE-A system has a length of 10 ms (307200 T _s ) and consists of 10 equally sized subframes (subframes). Numbers may be assigned to 10 subframes in one radio frame. Here, T _s represents the sampling time and is expressed as T _s = 1 / (2048 * 15 kHz). Each subframe has a length of 1 ms and consists of two slots. 20 slots in one radio frame may be sequentially numbered from 0 to 19. Each slot is 0.5ms long. The time for transmitting one subframe is defined as a transmission time interval (TTI). The time resource may be classified by a radio frame number (also called a radio frame index), a subframe number (also called a subframe number), a slot number (or slot index), and the like.

The radio frame may be configured differently according to the duplex mode. For example, in the FDD mode, since downlink transmission and uplink transmission are divided by frequency, a radio frame includes only one of a downlink subframe or an uplink subframe for a specific frequency band. In the TDD mode, since downlink transmission and uplink transmission are separated by time, a radio frame includes both a downlink subframe and an uplink subframe for a specific frequency band.

Table 1 illustrates a DL-UL configuration of subframes in a radio frame in the TDD mode.

DL-UL configuration

Downlink-to-Uplink Switch-point periodicity

Subframe number

0

One

2

3

4

5

6

7

8

9

0

5 ms

D

S

U

U

U

D

S

U

U

U

One

5 ms

D

S

U

U

D

D

S

U

U

D

2

5 ms

D

S

U

D

D

D

S

U

D

D

3

10 ms

D

S

U

U

U

D

D

D

D

D

4

10 ms

D

S

U

U

D

D

D

D

D

D

5

10 ms

D

S

U

D

D

D

D

D

D

D

6

5 ms

D

S

U

U

U

D

S

U

U

D

In Table 1, D represents a downlink subframe, U represents an uplink subframe, and S represents a special (special) subframe. The special subframe includes three fields of Downlink Pilot TimeSlot (DwPTS), Guard Period (GP), and Uplink Pilot TimeSlot (UpPTS). DwPTS is a time interval reserved for downlink transmission, and UpPTS is a time interval reserved for uplink transmission. Table 2 illustrates the configuration of a special subframe.

Special subframe configuration	Normal cyclic prefix in downlink			Extended cyclic prefix in downlink
	DwPTS	UpPTS		DwPTS	UpPTS
		Normal cyclic prefix in uplink	Extended cyclic prefix in uplink		Normal cyclic prefix in uplink	Extended cyclic prefix in uplink
0	6592T s	2192T s	2560T s	7680T s	2192T s	2560T s
One	19760T s			20480T s
2	21952T s			23040T s
3	24144T s			25600T s
4	26336T s			7680T s	4384T s	5120T s
5	6592T s	4384T s	5120T s	20480T s
6	19760T s			23040T s
7	21952T s			-	-	-
8	24144T s			-	-	-

2 illustrates an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system.

Referring to FIG. 2, a slot includes a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time domain and a plurality of resource blocks (RBs) in a frequency domain. An OFDM symbol may mean a symbol period. Referring to FIG. 2, a signal transmitted in each slot may be represented by a resource grid including N ^{DL / UL} _RB × N ^RB _sc subcarriers and N ^{DL / UL} _symb OFDM symbols. . Here, N ^DL _RB represents the number of resource blocks (RBs) in the downlink slot, and N ^UL _RB represents the number of _RBs in the UL slot. N ^DL _RB With N ^UL _RB Depends on the DL transmission bandwidth and the UL transmission bandwidth, respectively. N ^DL _symb represents the number of OFDM symbols in the downlink slot, and N ^UL _symb represents the number of OFDM symbols in the UL slot. N ^RB _sc represents the number of subcarriers constituting one RB.

The OFDM symbol may be called an OFDM symbol, a Single Carrier Frequency Division Multiplexing (SC-FDM) symbol, or the like according to a multiple access scheme. The number of OFDM symbols included in one slot may vary depending on the channel bandwidth and the length of the cyclic prefix (CP). For example, in case of a normal CP, one slot includes 7 OFDM symbols, whereas in case of an extended CP, one slot includes 6 OFDM symbols. Although FIG. 2 illustrates a subframe in which one slot is composed of seven OFDM symbols for convenience of description, embodiments of the present invention can be applied to subframes having different numbers of OFDM symbols in the same manner. Referring to FIG. 2, each OFDM symbol includes N ^{DL / UL} _RB × N ^RB _sc subcarriers in the frequency domain. The type of subcarriers may be divided into data subcarriers for data transmission, reference signal subcarriers for transmission of reference signals, null subcarriers for guard band or direct current (DC) components. . The DC component is mapped to a carrier frequency f ₀ during an OFDM signal generation process or a frequency upconversion process. The carrier frequency is also called a center frequency ( f _c ).

One RB is defined as N ^{DL / UL} _symb (e.g. 7) consecutive OFDM symbols in the time domain and is defined by N ^RB _sc (e.g. 12) consecutive subcarriers in the frequency domain. Is defined. For reference, a resource composed of one OFDM symbol and one subcarrier is called a resource element (RE) or tone. Therefore, one RB is composed of N ^{DL / UL} _symb × N ^RB _sc resource elements. Each resource element in the resource grid may be uniquely defined by an index pair ( k , 1 ) in one slot. k is an index given from 0 to N ^{DL / UL} _RB × N ^RB _sc −1 in the frequency domain, and l is an index given from 0 to N ^{DL / UL} _symb −1 in the time domain.

On the other hand, one RB is mapped to one physical resource block (PRB) and one virtual resource block (VRB), respectively. The PRB is defined as N ^{DL / UL} _symb contiguous OFDM symbols (e.g. 7) or SC-FDM symbols in the time domain and N ^RB _sc contiguous (e.g. 12) in the frequency domain Is defined by subcarriers. Therefore, one PRB is composed of N ^{DL / UL} _symb × N ^RB _sc resource elements. Two ^RBs , each occupied by N ^RB _sc consecutive subcarriers in one subframe and one in each of two slots of the subframe, are referred to as a PRB pair. Two RBs constituting a PRB pair have the same PRB number (or also referred to as a PRB index).

When the UE is powered on or wants to access a new cell, the UE acquires time and frequency synchronization with the cell and detects a ^cell's physical layer cell identity N ^cell _ID . Perform an initial cell search procedure. To this end, the UE receives a synchronization signal from the eNB, for example, a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) to synchronize with the eNB, and synchronizes with the eNB. , ID) and the like can be obtained.

Specifically, since the PSS is transmitted every 5 ms, the UE detects the PSS to know that the corresponding subframe is one of the subframe 0 and the subframe 5, but the subframe is specifically the subframe 0 and the subframe 5. I can not know. Therefore, the UE does not recognize the boundary of the radio frame only by the PSS. That is, frame synchronization cannot be obtained only by PSS. The UE detects the boundary of the radio frame by detecting the SSS transmitted twice in one radio frame but transmitted as different sequences.

The UE, which has performed a cell discovery process using PSS / SSS to determine the time and frequency parameters required to perform demodulation of DL signals and transmission of UL signals at an accurate time point, can also be determined from the eNB. System information necessary for system configuration must be obtained to communicate with the eNB.

System information is configured by a Master Information Block (MIB) and System Information Blocks (SIBs). Each system information block includes a collection of functionally related parameters, and includes a master information block (MIB), a system information block type 1 (SIB1), and a system information block type according to the included parameters. 2 (System Information Block Type 2, SIB2) and SIB3 to SIB8. The MIB contains the most frequently transmitted parameters that are necessary for the UE to have initial access to the eNB's network. SIB1 includes not only information on time domain scheduling of other SIBs, but also parameters necessary for determining whether a specific cell is a cell suitable for cell selection.

The UE may receive the MIB via a broadcast channel (eg, PBCH). The MIB includes a downlink system bandwidth (dl-Bandwidth, DL BW), a PHICH configuration, and a system frame number (SFN). Therefore, the UE can know the information on the DL BW, SFN, PHICH configuration explicitly by receiving the PBCH. On the other hand, the information that the UE implicitly (implicit) through the reception of the PBCH includes the number of transmit antenna ports of the eNB. Information about the number of transmit antennas of the eNB is implicitly signaled by masking (eg, XOR operation) a sequence corresponding to the number of transmit antennas to a 16-bit cyclic redundancy check (CRC) used for error detection of the PBCH.

The DL carrier frequency and the corresponding system bandwidth may be obtained by the PBCH, and the UL carrier frequency and the corresponding system bandwidth may be obtained through the system information that is the DL signal. For example, the UE may acquire a system information block type 2 (SystemInformationBlockType2, SIB2) to determine the entire UL system band that can be used for UL transmission through UL-carrier frequency and UL-bandwidth information in the SIB2. .

After the initial cell discovery, the UE may perform a random access procedure to complete the access to the eNB. To this end, the UE may transmit a preamble through a physical random access channel (PRACH) and receive a response message for the preamble through a PDCCH and a PDSCH. In case of contention based random access, additional PRACH transmission and contention resolution procedure such as PDCCH and PDSCH corresponding to the PDCCH may be performed.

After performing the above-described procedure, the UE may perform PDCCH / PDSCH reception and PUSCH / PUCCH transmission as a general uplink / downlink signal transmission procedure.

The random access process is also referred to as a random access channel (RACH) process. The random access procedure is used for initial access, the random access procedure is used for various purposes such as initial access, uplink synchronization coordination, resource allocation, handover, and the like. The random access process is classified into a contention-based process and a dedicated (ie non-competition-based) process. The contention-based random access procedure is generally used, including initial access, and the dedicated random access procedure is limited to handover and the like. In the contention-based random access procedure, the UE randomly selects a RACH preamble sequence. Therefore, it is possible for a plurality of UEs to transmit the same RACH preamble sequence at the same time, which requires a contention cancellation process later. On the other hand, in the dedicated random access process, the UE uses the RACH preamble sequence that is allocated only to the UE by the eNB. Therefore, the random access procedure can be performed without collision with another UE.

The contention-based random access procedure includes four steps. Hereinafter, the messages transmitted in steps 1 to 4 may be referred to as messages 1 to 4 (Msg1 to Msg4), respectively.

Step 1: RACH preamble (via PRACH) (UE to eNB)

Step 2: random access response (RAR) (via PDCCH and PDSCH) (eNB to UE)

Step 3: Layer 2 / Layer 3 message (via PUSCH) (UE to eNB)

Step 4: Contention Resolution Message (eNB to UE)

The dedicated random access procedure includes three steps. Hereinafter, the messages transmitted in steps 0 to 2 may be referred to as messages 0 to 2 (Msg0 to Msg2), respectively. Although not shown, uplink transmission (ie, step 3) corresponding to the RAR may also be performed as part of the random access procedure. The dedicated random access procedure may be triggered using a PDCCH (hereinafter, referred to as a PDCCH order) for the purpose of instructing the base station to transmit the RACH preamble.

Step 0: RACH preamble allocation via dedicated signaling (eNB to UE)

Step 1: RACH preamble (via PRACH) (UE to eNB)

Step 2: Random Access Response (RAR) (via PDCCH and PDSCH) (eNB to UE)

After transmitting the RACH preamble, the UE attempts to receive a random access response (RAR) within a pre-set time window. Specifically, the UE attempts to detect a PDCCH (hereinafter, RA-RNTI PDCCH) having a random access RNTI (RA-RNTI) (eg, CRC in the PDCCH is masked to RA-RNTI) within a time window. Upon detecting the RA-RNTI PDCCH, the UE checks whether there is a RAR for itself in the PDSCH corresponding to the RA-RNTI PDCCH. The RAR includes timing advance (TA) information indicating timing offset information for UL synchronization, UL resource allocation information (UL grant information), a temporary identifier (eg, temporary cell-RNTI, TC-RNTI), and the like. The UE may perform UL transmission (eg, Msg3) according to the resource allocation information and the TA value in the RAR. HARQ is applied to UL transmission corresponding to the RAR. Therefore, after transmitting the Msg3, the UE may receive reception response information (eg, PHICH) corresponding to the Msg3.

3 illustrates a downlink subframe structure used in a wireless communication system.

Referring to FIG. 3, a DL subframe is divided into a control region and a data region in the time domain. Referring to FIG. 3, up to three (or four) OFDM symbols located at the front of the first slot of a subframe correspond to a control region to which a control channel is allocated. Hereinafter, a resource region available for PDCCH transmission in a DL subframe is called a PDCCH region. The remaining OFDM symbols other than the OFDM symbol (s) used as the control region correspond to a data region to which a Physical Downlink Shared CHannel (PDSCH) is allocated. Hereinafter, a resource region available for PDSCH transmission in a DL subframe is called a PDSCH region. Examples of DL control channels used in 3GPP LTE include a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), a physical hybrid ARQ indicator channel (PHICH), and the like. The PCFICH is transmitted in the first OFDM symbol of a subframe and carries information about the number of OFDM symbols used for transmission of a control channel within the subframe. The PHICH carries a Hybrid Automatic Repeat Request (HARQ) ACK / NACK (acknowledgment / negative-acknowledgment) signal as a response to the UL transmission.

Control information transmitted through the PDCCH is referred to as downlink control information (DCI). DCI includes resource allocation information and other control information for the UE or UE group. The transmission format and resource allocation information of a downlink shared channel (DL-SCH) may also be called DL scheduling information or a DL grant, and may be referred to as an uplink shared channel (UL-SCH). The transmission format and resource allocation information is also called UL scheduling information or UL grant. The DCI carried by one PDCCH has a different size and use depending on the DCI format, and its size may vary depending on a coding rate. In the current 3GPP LTE system, various formats such as formats 0 and 4 for uplink and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B, 2C, 3, and 3A are defined for uplink. Hopping flag, RB allocation, modulation coding scheme (MCS), redundancy version (RV), new data indicator (NDI), transmit power control (TPC), and cyclic shift DMRS Control information such as shift demodulation reference signal (UL), UL index, CQI request, DL assignment index, HARQ process number, transmitted precoding matrix indicator (TPMI), and precoding matrix indicator (PMI) information The selected combination is transmitted to the UE as downlink control information.

A plurality of PDCCHs may be transmitted in the control region. The UE may monitor the plurality of PDCCHs. The eNB determines the DCI format according to the DCI to be transmitted to the UE, and adds a cyclic redundancy check (CRC) to the DCI. The CRC is masked (or scrambled) with an identifier (eg, a radio network temporary identifier (RNTI)) depending on the owner or purpose of use of the PDCCH. For example, when the PDCCH is for a specific UE, an identifier (eg, cell-RNTI (C-RNTI)) of the UE may be masked to the CRC. If the PDCCH is for a paging message, a paging identifier (eg, paging-RNTI (P-RNTI)) may be masked to the CRC. When the PDCCH is for system information (more specifically, a system information block (SIB)), a system information RNTI (SI-RNTI) may be masked to the CRC. If the PDCCH is for a random access response, a random access-RNTI (RA-RNTI) may be masked to the CRC. CRC masking (or scramble) includes, for example, XORing the CRC and RNTI at the bit level.

The PDCCH is transmitted on an aggregation of one or a plurality of consecutive control channel elements (CCEs). CCE is a logical allocation unit used to provide a PDCCH with a coding rate based on radio channel conditions. The CCE corresponds to a plurality of resource element groups (REGs). For example, one CCE corresponds to nine REGs and one REG corresponds to four REs. Four QPSK symbols are mapped to each REG. The resource element RE occupied by the reference signal RS is not included in the REG. Thus, the number of REGs within a given OFDM symbol depends on the presence of RS. The REG concept is also used for other downlink control channels (ie, PCFICH and PHICH). The DCI format and the number of DCI bits are determined according to the number of CCEs. CCEs are numbered and used consecutively, and to simplify the decoding process, a PDCCH having a format consisting of n CCEs can be started only in a CCE having a number corresponding to a multiple of n. The number of CCEs used for transmission of a specific PDCCH is determined by the network or eNB according to the channel state. For example, in case of PDCCH for a UE having a good downlink channel (eg, adjacent to an eNB), one CCE may be sufficient. However, in case of PDCCH for a UE having a poor channel (eg, near the cell boundary), eight CCEs may be required to obtain sufficient robustness. In addition, the power level of the PDCCH may be adjusted according to the channel state.

In the 3GPP LTE / LTE-A system, a set of CCEs in which a PDCCH can be located for each UE is defined. The collection of CCEs in which a UE can discover its PDCCH is referred to as a PDCCH search space, simply a search space (SS). An individual resource to which a PDCCH can be transmitted in a search space is called a PDCCH candidate. The collection of PDCCH candidates that the UE will monitor is defined as a search space. The search space may have a different size, and a dedicated search space and a common search space are defined. The dedicated search space is a UE-specific search space (USS) and is configured for each individual UE. A common search space (CSS) is set for a plurality of UEs.

The eNB sends the actual PDCCH (DCI) on any PDCCH candidate in the search space, and the UE monitors the search space to find the PDCCH (DCI). Here, monitoring means attempting decoding of each PDCCH in a corresponding search space according to all monitored DCI formats. The UE may detect its own PDCCH by monitoring the plurality of PDCCHs. Basically, since the UE does not know where its PDCCH is transmitted, every subframe attempts to decode the PDCCH until all PDCCHs of the corresponding DCI format have detected a PDCCH having their own identifiers. It is called blind detection (blind decoding).

For example, a specific PDCCH is masked with a cyclic redundancy check (CRC) with a Radio Network Temporary Identity (RNTI) of "A", a radio resource (eg, frequency location) of "B" and a transmission of "C". Assume that information about data to be transmitted using format information (eg, transport block size, modulation scheme, coding information, etc.) is transmitted through a specific DL subframe. The UE monitors the PDCCH using its own RNTI information, and the UE having the RNTI "A" detects the PDCCH, and the PDSCH indicated by "B" and "C" through the received PDCCH information. Receive

Meanwhile, a PDCCH may be additionally allocated in a data region (eg, a resource region for PDSCH). The PDCCH allocated to the data region is called an EPDCCH. As illustrated, by additionally securing control channel resources through the EPDCCH, scheduling constraints due to limited control channel resources in the PDCCH region may be relaxed. Like the PDCCH, the EPDCCH carries a DCI. For example, the EPDCCH may carry downlink scheduling information and uplink scheduling information. For example, the UE may receive an EPDCCH and receive data / control information through a PDSCH corresponding to the EPDCCH. In addition, the UE may receive the EPDCCH and transmit data / control information through a PUSCH corresponding to the EPDCCH. The EPDCCH / PDSCH may be allocated from the first OFDM symbol of the subframe according to the cell type. Unless otherwise specified, in the present specification, the PDCCH includes both PDCCH and EPDCCH.

4 illustrates an example of an uplink (UL) subframe structure used in a wireless communication system.

Referring to FIG. 4, the UL subframe may be divided into a control region and a data region in the frequency domain. One or several physical uplink control channels (PUCCHs) may be allocated to the control region to carry uplink control information (UCI). One or several physical uplink shared channels (PUSCHs) may be allocated to a data region of a UL subframe to carry user data.

In the UL subframe, subcarriers having a long distance based on a direct current (DC) subcarrier are used as a control region. In other words, subcarriers located at both ends of the UL transmission bandwidth are allocated for transmission of uplink control information. The DC subcarrier is a component that is not used for signal transmission and is mapped to a carrier frequency f ₀ during frequency upconversion. The PUCCH for one UE is allocated to an RB pair belonging to resources operating at one carrier frequency in one subframe, and the RBs belonging to the RB pair occupy different subcarriers in two slots. The PUCCH allocated in this way is expressed as that the RB pair allocated to the PUCCH is frequency hopped at the slot boundary. However, if frequency hopping is not applied, RB pairs occupy the same subcarrier.

PUCCH may be used to transmit the following control information.

SR (Scheduling Request): Information used to request an uplink UL-SCH resource. It is transmitted using OOK (On-Off Keying) method.

HARQ-ACK: A response to a PDCCH and / or a response to a downlink data packet (eg, codeword) on a PDSCH. This indicates whether the PDCCH or PDSCH is successfully received. HARQ-ACK 1 bit is transmitted in response to a single downlink codeword, HARQ-ACK 2 bits are transmitted in response to two downlink codewords.

For example, HARQ-ACK for a PDCCH or PDSCH received in one subframe on a single carrier may be represented by 1 bit. When the UE detects the PDCCH and successfully decodes the PDSCH, it feeds back a bit (eg, 1b) indicating an ACK, and if the UE fails to detect the PDCCH or fails to decode the PDSCH, it feeds back a bit (eg, 0b) indicating a NACK. . HARQ-ACK for PDCCH / PDSCHs on multiple carriers or PDCCH / PDSCHs in multiple subframes may be represented by 2 bits. For example, when feeding back HARQ-ACK for PDCCH / PDSCHs on two carriers or within two subframes, one of the two carriers or two subframes detects the PDCCH and decodes the PDSCH accordingly. In this case, a corresponding ACK / NACK bit may be set according to the decoding result of the PDSCH. If the PDCCH is not detected in the other of the two carriers or two subframes, the corresponding HARQ-ACK corresponds to DTX, but since the UE must feed back a 2-bit HARQ-ACK to the eNB, the remaining bits of the 2-bit HARQ-ACK Is set to NACK to feed back to the eNB.

HARQ-ACK response includes a positive ACK (simple, ACK), negative ACK (hereinafter, NACK), DTX (Discontinuous Transmission) or NACK / DTX. Here, the term HARQ-ACK is mixed with HARQ ACK / NACK, ACK / NACK.

Channel State Information (CSI): Feedback information for the downlink channel. CSI consists of channel quality information (CQI), precoding matrix indicator (PMI), precoding type indicator (PTI), and / or rank indication (RI) Can be. Of these, Multiple Input Multiple Output (MIMO) -related feedback information includes RI and PMI. RI means the number of streams or the number of layers that a UE can receive through the same time-frequency resource. PMI is a value reflecting a space characteristic of a channel and indicates an index of a precoding matrix that a UE prefers for downlink signal transmission based on a metric such as SINR. The CQI is a value indicating the strength of the channel and typically indicates the received SINR that the UE can obtain when the eNB uses PMI.

In particular, the PUCCH allocated for SR transmission is called SR PUCCH, and the PUCCH allocated for HARQ-ACK transmission is called ACK / NACK PUCCH, and the PUCCH allocated for CSI transmission is called CSI PUCCH.

5 is a diagram for describing single carrier communication and multicarrier communication. In particular, FIG. 5 (a) shows a subframe structure of a single carrier and FIG. 5 (b) shows a subframe structure of a multicarrier.

Referring to FIG. 5 (a), a general wireless communication system performs data transmission or reception through one DL band and one UL band corresponding thereto (in a frequency division duplex (FDD) mode) or In addition, a predetermined radio frame is divided into an uplink time unit and a downlink time unit in a time domain, and data transmission or reception is performed through an uplink / downlink time unit (time division duplex). , TDD) mode). However, in recent wireless communication systems, the introduction of a carrier aggregation or bandwidth aggregation technique using a larger UL / DL bandwidth by collecting a plurality of UL and / or DL frequency blocks in order to use a wider frequency band has been discussed. have. Carrier aggregation (CA) performs DL or UL communication by using a plurality of carrier frequencies, and performs DL or UL communication by putting a fundamental frequency band divided into a plurality of orthogonal subcarriers on one carrier frequency. It is distinguished from an orthogonal frequency division multiplexing (OFDM) system. Hereinafter, each carrier aggregated by carrier aggregation is called a component carrier (CC). Referring to FIG. 5 (b), three 20 MHz CCs may be gathered in the UL and the DL to support a 60 MHz bandwidth. Each of the CCs may be adjacent or non-adjacent to each other in the frequency domain. 5 (b) shows a case where both the bandwidth of the UL CC and the bandwidth of the DL CC are the same and symmetrical, the bandwidth of each CC may be determined independently. In addition, asymmetrical carrier aggregation in which the number of UL CCs and the number of DL CCs are different is possible. A DL / UL CC limited to a specific UE may be referred to as a configured serving UL / DL CC in a specific UE.

Meanwhile, the 3GPP LTE-A standard uses the concept of a cell to manage radio resources. A "cell" associated with a radio resource is defined as a combination of DL resources and UL resources, that is, a combination of a DL CC and a UL CC. The cell may be configured with DL resources alone or with a combination of DL resources and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL CC) and the carrier frequency of the UL resource (or UL CC) is indicated by system information. Can be. For example, a combination of DL and UL resources may be indicated by a System Information Block Type 2 (SIB2) linkage. Here, the carrier frequency means a center frequency of each cell or CC. Hereinafter, a cell operating on a primary frequency is referred to as a primary cell (Pcell) or a PCC, and a cell operating on a secondary frequency (or SCC) is referred to as a secondary cell. cell, Scell) or SCC. The carrier corresponding to the Pcell in downlink is called a DL primary CC (DL PCC), and the carrier corresponding to the Pcell in the uplink is called a UL primary CC (DL PCC). Scell refers to a cell that can be configured after RRC (Radio Resource Control) connection establishment is made and can be used for providing additional radio resources. Depending on the capabilities of the UE, the Scell may form a set of serving cells for the UE with the Pcell. The carrier corresponding to the Scell in downlink is called a DL secondary CC (DL SCC), and the carrier corresponding to the Scell in the uplink is called a UL secondary CC (UL SCC). In case of the UE that is in the RRC_CONNECTED state but the carrier aggregation is not configured or does not support the carrier aggregation, there is only one serving cell configured only for the Pcell.

The eNB may be used for communication with the UE by activating some or all of the serving cells configured in the UE or by deactivating some. The eNB may change a cell that is activated / deactivated and may change the number of cells that are activated / deactivated. Once the eNB assigns a cell-specific or UE-specifically available cell to a UE, once the cell assignment for the UE is fully reconfigured or the UE does not handover, At least one of the cells is not deactivated. A cell that is not deactivated may be referred to as a Pcell unless a global reset of cell allocation for the UE is performed. A cell that an eNB can freely activate / deactivate may be referred to as an Scell. Pcell and Scell may be classified based on control information. For example, specific control information may be set to be transmitted / received only through a specific cell. This specific cell may be referred to as a Pcell, and the remaining cell (s) may be referred to as an Scell.

6 illustrates states of cells in a system supporting carrier aggregation.

In FIG. 6, a configured cell is a cell in which carrier aggregation is performed for a UE based on a measurement report from another eNB or a UE among cells of an eNB, and is configured for each UE. The cell configured for the UE may be referred to as a serving cell from the viewpoint of the UE. In the cell configured in the UE, that is, the serving cell, resources for ACK / NACK transmission for PDSCH transmission are reserved in advance. The activated cell is a cell configured to be actually used for PDSCH / PUSCH transmission among cells configured in the UE, and is performed on a cell in which CSI reporting and SRS transmission are activated for PDSCH / PUSCH transmission. The deactivated cell is a cell configured not to be used for PDSCH / PUSCH transmission by the operation of a eNB or a timer. When the cell is deactivated, CSI reporting and SRS transmission are also stopped in the cell. For reference, in FIG. 6, CI means a serving cell index, and CI = 0 is applied for a Pcell. The serving cell index is a short identity used to identify the serving cell, for example, one of an integer from 0 to 'the maximum number of carrier frequencies that can be set to the UE at one time-1'. May be assigned to one serving cell as the serving cell index. That is, the serving cell index may be referred to as a logical index used to identify a specific serving cell only among cells allocated to the UE, rather than a physical index used to identify a specific carrier frequency among all carrier frequencies.

As mentioned above, the term cell used in carrier aggregation is distinguished from the term cell which refers to a certain geographic area where communication service is provided by one eNB or one antenna group.

Unless otherwise specified, a cell referred to in the present invention refers to a cell of carrier aggregation which is a combination of a UL CC and a DL CC.

In the case of communication using a single carrier, since only one serving cell exists, the PDCCH carrying the UL / DL grant and the corresponding PUSCH / PDSCH are transmitted in the same cell. In other words, in the case of FDD under a single carrier situation, the PDCCH for the DL grant for the PDSCH to be transmitted in a specific DL CC is transmitted in the specific CC, and the PDSCH for the UL grant for the PUSCH to be transmitted in the specific UL CC is determined by the specific CC. It is transmitted on the DL CC linked with the UL CC. In the case of TDD under a single carrier situation, the PDCCH for the DL grant for the PDSCH to be transmitted in a specific CC is transmitted in the specific CC, and the PDSCH for the UL grant for the PUSCH to be transmitted in the specific CC is transmitted in the specific CC.

In contrast, in a multi-carrier system, since a plurality of serving cells can be configured, UL / DL grant can be allowed to be transmitted in a serving cell having a good channel condition. As such, when a cell carrying UL / DL grant, which is scheduling information, and a cell in which UL / DL transmission corresponding to a UL / DL grant is performed, this is called cross-carrier scheduling.

In the following description, a case where a cell is scheduled from a corresponding cell itself, that is, itself and a case where a cell is scheduled from another cell, is called self-CC scheduling and cross-CC scheduling, respectively.

3GPP LTE / LTE-A may support a merge of multiple CCs and a cross carrier-scheduling operation based on the same for improving data rate and stable control signaling.

When cross-carrier scheduling (or cross-CC scheduling) is applied, downlink allocation for DL CC B or DL CC C, that is, PDCCH carrying DL grant is transmitted to DL CC A, and the corresponding PDSCH is DL CC B or DL CC C may be transmitted. For cross-CC scheduling, a carrier indicator field (CIF) may be introduced. The presence or absence of the CIF in the PDCCH may be set in a semi-static and UE-specific (or UE group-specific) manner by higher layer signaling (eg, RRC signaling). The baseline of PDCCH transmission is summarized as follows.

■ CIF disabled: PDCCH on DL CC allocates PDSCH resources on the same DL CC or PUSCH resources on one linked UL CC

■ No CIF

■ LTE PDCCH structure (same coding, same CCE-based resource mapping) and same as DCI format

■ CIF enabled: PDCCH on DL CC can allocate PDSCH / PUSCH resource on a specific DL / UL CC among a plurality of merged DL / UL CCs using CIF

Extended LTE DCI format with CIF

CIF (if set) is a fixed x-bit field (eg x = 3)

-CIF (if set) position is fixed regardless of DCI format size

Reuse LTE PDCCH structure (same coding, same CCE-based resource mapping)

One or more scheduling cells may be configured for one UE, and one of these scheduling cells may be a PCC dedicated to specific DL control signaling and UL PUCCH transmission. The scheduling cell set may be set in a UE-specific, UE group-specific or cell-specific manner. In the case of a scheduling cell, it may be configured to at least schedule itself. In other words, the scheduling cell may be its own scheduled cell. In the present invention, a cell carrying a PDCCH is called a scheduling cell, a monitoring cell, or an MCC, and a cell carrying a PDSCH / PUSCH scheduled by the PDCCH is called a scheduled cell.

The scheduling cell is part of all carrier aggregated cells, and includes a DL CC, and the UE detects / decodes a PDCCH only on the corresponding DL CC. Here, PDSCH / PUSCH of a scheduling cell or a scheduled cell refers to a PDSCH / PUSCH configured to be transmitted on a corresponding cell, and PHICH of a scheduling cell or a scheduled cell refers to an ACK / NACK for a PUSCH transmitted on a corresponding cell. It means PHICH to carry.

After reception / transmission of scheduling, data transmission / reception according to the scheduling, and ACK / NACK reception / transmission for the data transmission are performed, a time delay occurs until data retransmission is performed. This time delay occurs because of the time required for channel propagation delay, data decoding / encoding. Therefore, when new data is sent after the current HARQ process is completed, a space delay occurs in the data transmission due to a time delay. Therefore, a plurality of independent HARQ processes (HARQ process, HARQ) is used to prevent the occurrence of a gap in the data transmission during the time delay period. For example, when the interval between initial transmission and retransmission is seven subframes, seven independent HARQ processes may be operated to transmit data without a space. Multiple parallel HARQ processes allow UL / DL transmissions to be performed continuously while waiting for HARQ feedback for previous UL / DL transmissions. Each HARQ process is associated with a HARQ buffer of a medium access control (MAC) layer. Each HARQ process manages state variables related to the number of transmissions of the MAC Physical Data Block (PDU) in the buffer, HARQ feedback for the MAC PDU in the buffer, the current redundancy version, and the like.

The transmission timing (or HARQ timing) of ACK / NACK for DL transmission will be described. The UE may receive a PDCCH indicating one or more PDSCH or SPS releases on M DL subframes (SF) (M ≧ 1). Each PDSCH signal may include one or more (eg, two) transport blocks (TBs) according to a transmission mode. If there are PDSCH signals and / or SPS release PDCCH signals in the M DL subframes, the UE goes through a process for ACK / NACK transmission (eg, ACK / NACK (payload) generation, ACK / NACK resource allocation, etc.) ACK / NACK is transmitted through one UL subframe corresponding to M DL subframes. The ACK / NACK includes reception response information for the PDSCH signal and / or the SPS release PDCCH signal. The ACK / NACK is basically transmitted through the PUCCH, but is transmitted through the PUSCH when there is a PUSCH assignment at the time of the ACK / NACK transmission. When a plurality of CCs are configured for the UE, the PUCCH is transmitted only on the Pcell, and the PUSCH is transmitted on the scheduled CC. Various PUCCH formats may be used for ACK / NACK transmission. Various methods such as ACK / NACK bundling and ACK / NACK channel selection (CHsel) may be used to reduce the number of ACK / NACK bits.

M = 1 in FDD and M is an integer greater than or equal to 1 in TDD. The relationship between M DL subframes and a UL subframe in which ACK / NACK is transmitted in TDD is given by a Downlink Association Set Index (DASI).

Table 3 shows DASI (K: {k ₀ , k ₁ , ..., k _M-1 }) defined in LTE (-A). If there is a PDCCH indicating PDSCH transmission and / or Semi-Persistent Scheduling release in subframe nk (k∈K), the UE transmits ACK / NACK in subframe n. DASI (for convenience, d _F ) = 4 in FDD.

TDD UL-DLConfiguration											Subframe n
	0	One	2	3	4	5	6	7	8	9
0	-	-	6	-	4	-	-	6	-	4
One	-	-	7, 6	4	-	-	-	7, 6	4	-
2	-	-	8, 7, 4, 6	-	-	-	-	8, 7, 4, 6	-	-
3	-	-	7, 6, 11	6, 5	5, 4	-	-	-	-	-
4	-	-	12, 8, 7, 11	6, 5, 4, 7	-	-	-	-	-	-
5	-	-	13, 12, 9, 8, 7, 5, 4, 11, 6	-	-	-	-	-	-	-
6	-	-	7	7	5	-	-	7	7	-

When operating in the TDD scheme, the UE should transmit ACK / NACK signals for one or more DL transmissions (eg, PDSCHs) received through M DL subframes (SFs) through one UL SF. A method of transmitting ACK / NACK for a plurality of DL SFs through one UL SF is as follows.

1) ACK / NACK bundling: ACK / NACK bits for a plurality of data units (e.g. PDSCH, semi-persistent scheduling (SPS) release PDCCH, etc.) are logical operations (e.g., Logical-AND operation). For example, if all data units are successfully decoded, the receiving end (eg, UE) sends an ACK signal. On the other hand, if decoding (or detection) of any of the data units fails, the UE transmits a NACK signal or nothing.

2) channel selection (CHsel): A UE receiving a plurality of data units (eg, PDSCH, SPS release PDCCH, etc.) occupies a plurality of PUCCH resources for ACK / NACK transmission. The ACK / NACK response for the plurality of data units is identified by the combination of the PUCCH resource used for the actual ACK / NACK transmission and the transmitted ACK / NACK content (eg, bit value, QPSK symbol value). The channel selection method is also referred to as an ACK / NACK selection method and a PUCCH selection method.

In 3GPP LTE / LTE-A system, there are two transmission schemes, an open-loop MIMO operated without feedback of channel information and a closed-loop MIMO using feedback of channel information. In the closed loop MIMO, the transmitter and the receiver perform beamforming based on channel information, that is, CSI, to obtain multiplexing gains of the MIMO antenna, respectively. The time and frequency resources that can be used by the UE to report CSI are controlled by the eNB. For example, the eNB instructs the UE to feed back the downlink CSI by allocating a PUCCH or a PUSCH to obtain the downlink CSI.

CSI reporting is set up periodically or aperiodically. Periodic CSI reporting is a special case (e.g., when the UE is not configured for simultaneous PUSCH and PUCCH transmission and the PUCCH transmission time collides with a subframe with PUSCH allocation). If not, it is sent by the UE on PUCCH. Since the RI of the CSI is determined to be dominant by long term fading, it is fed back from the UE to the eNB in a longer period than the PMI and the CQI. On the other hand, the aperiodic CSI report is transmitted on the PUSCH. Aperiodic CSI reporting is triggered by a CSI request field included in DCI (eg, DCI of DCI format 0 or 4) (hereinafter, referred to as uplink DCI format) for scheduling of uplink data. do. A UE that has decoded an uplink DCI format or random access response grant for a specific serving cell (hereinafter, serving cell c ) in subframe n , is configured such that the corresponding CSI request field is triggered to trigger CSI reporting. If the CSI request field is not reserved, aperiodic CSI reporting is performed using the PUSCH in subframe n + k on the serving cell c . The PUSCH is a PUSCH transmitted in subframe n + k in accordance with the UL DCI format decoded in sub frame n. In the case of FDD, k = 4. For TDD, k is given by the following table.

TDD UL / DLConfiguration	subframe number n
	0	One	2	3	4	5	6	7	8	9
0	4	6				4	6
One		6			4		6			4
2				4					4
3	4								4	4
4									4	4
5									4
6	7	7				7	7			5

For example, if a UE having a TDD UL / DL configuration of 6 detects an uplink DCI format for serving cell c in subframe 9, the UE detects subframe 9 + 5, that is, the uplink DCI format is detected. In subframe 4 of the radio frame following the radio frame including subframe 9, aperiodic CSI reporting triggered by the CSI request field in the detected uplink DCI format is performed on the PUSCH of the serving cell c .

The length of the CSI request field is 1 bit or 2 bits. If the CSI request field is 1 bit, the CSI request field set to '1' triggers aperiodic CSI reporting for the serving cell c . If the CSI request field is 2 bits and a UE configured with one or more Scells is set to transmission mode 1-9 for all cells, aperiodic CSI reporting corresponding to the values in the following table is triggered. The following table shows a CSI request field for a PDCCH / EPDCCH with an uplink DCI format in a UE specific search space.

Value of CSI request field	Description
'00'	No aperiodic CSI report is triggered
'01'	Aperiodic CSI report is triggered for serving cell c
'10'	Aperiodic CSI report is triggered for a 1 st set of serving cells configured by higher layers
'11'	Aperiodic CSI report is triggered for a 2 nd set of serving cells configured by higher layers

In the above table, for which serving cell (s) aperiodic CSI reporting is triggered by CSI request field '10' and / or CSI request field '11' may be set by a higher layer signal (e.g., RRC signal). have. The upper layer signal includes an 8-bit bitmap indicating a cell (s) to be triggered by the CSI request field '10' and an 8-bit bitmap indicating a cell (s) to be triggered by the CSI request field '11'. It may include. In each bitmap, bit 0, which is the lowest bit, to bit 7, which is the highest bit, correspond one-to-one to cells with a serving cell index of 0 (that is, Pcell) to cells with a serving cell index of 7. A cell corresponding to a bit set to 1 in the bitmap for the CSI request field '10' means a cell in which an aperiodic CSI report is triggered by the CSI request field value '10', and a cell corresponding to a bit set to 0 Denotes a cell in which aperiodic CSI reporting is not triggered by the CSI request field value '10'. A cell corresponding to a bit set to 1 in the bitmap for the CSI request field '11' means a cell in which an aperiodic CSI report is triggered by the CSI request field value '11', and a cell corresponding to a bit set to 0 Denotes a cell in which aperiodic CSI reporting is not triggered by the CSI request field value '11'.

Recently, applying CoMP technology to LTE / LTE-A system has been considered. CoMP technology involves a plurality of nodes. When CoMP technology is introduced into the LTE / LTE-A system, a new transmission mode associated with CoMP technology may be defined. There may be various configurations of CSI-RSs received by the UE depending on how a plurality of nodes participate in the communication. For this reason, in the existing LTE system, up to one CSI-RS configuration or CSI-RS resource configuration in which the UE should assume non-zero transmission power for CSI-RS could be used. In case of a UE set to CoMP mode, the maximum number of CSI resource settings that can be used for the UE is more than one. When the UE is set to a mode that can be set with one or more CSI-RS resource settings, that is, when the UE is set to CoMP mode, the UE can provide information about one or more CSI-RS resource settings. A higher layer signal may be received. When not only CoMP but also carrier aggregation (hereinafter CA) is configured for the UE, one or more CSI-RS resource configurations may be used for each serving cell.

In the existing LTE / LTE-A system, the UE transmits / receives a signal to / from one node on a specific serving cell. That is, in the existing LTE / LTE-A system, since only one radio link exists on one serving cell, only one CSI for one serving cell could be calculated by the UE. On the other hand, in CoMP involving a plurality of nodes, the downlink channel state may be different for each node or a combination of nodes. CSI is associated with CSI-RS resources because CSI-RS resource configuration may vary depending on the node or combination of nodes. In addition, depending on the interference environment between the nodes participating in the CoMP channel state may be different. In other words, when CoMP is configured, the maximum number of CSIs that can be calculated for each serving cell of the UE may be an integer greater than 1 since it may be measured by the UE for each node or a combination of nodes and CSI may exist for each interference environment. How the CSI should report the CSI in order for the UE to obtain the CSI may be set by the upper layer. If CoMP is set, not only one CSI can be calculated by the UE but also a plurality of CSIs. Therefore, if the UE is set to CoMP mode, CSI reporting for one or more CSI can be configured for each serving cell of the UE for periodic or aperiodic CSI reporting.

Meanwhile, as mentioned above, in CoMP, CSI is associated with a CSI-RS resource used for channel measurement and a resource used for interference measurement (hereinafter, referred to as an interference measurement (IM) resource). Hereinafter, the association of one CSI-RS resource for signal measurement and one IM resource for interference measurement is called a CSI process. That is, the CSI process may be associated with one CSI-RS resource and IM resource (IM resource, IMR).

It is preferable that the eNB to which the UE is connected or the eNB (hereinafter, the serving eNB) managing the node of the cell where the UE is located transmits no signal on the IM resource. Thus, the IM resource may be configured for the UE in the same manner as the zero-power CSI-RS. For example, the eNB may inform the UE of the resource elements used by the UE for interference measurement using a 16-bit bitmap and CSI-RS subframe configuration indicating the zero power CSI-RS pattern described above. As such, when the IM resource is explicitly set to the UE, the UE measures the interference in the IM resource and assumes that the interference is an interference in the CSI reference resource that is the basis of the CSI measurement, and calculates the CSI. More specifically, the UE may perform channel measurement based on CSI-RS or CRS and perform interference measurement based on IM resources, thereby obtaining CSI based on the channel measurement and the interference measurement.

Thus, one CSI reported by the UE may correspond to one CSI process. Each CSI process may have an independent CSI feedback setting. Independent feedback setting means a feedback mode, a feedback period, and a feedback offset. The feedback offset corresponds to a starting subframe with feedback among the subframes in the radio frame. The feedback mode depends on whether the CQI included in the fed back CSI among the RI, CQI, PMI, and TPMI is the CQI for the wideband, the CQI for the subband, or the CQI for the subband selected by the UE. The CSI may be defined differently depending on whether the CSI includes a PMI, whether a CSI includes a single PMI, or a plurality of PMIs.

If the CSI request field is 2 bits and the UE is set to a mode in which one or more CSI processes can be configured for at least one cell (eg, transmission mode 10), then aperiodic CSI reporting corresponding to the values in the following table is triggered. The following table shows a CSI request field for a PDCCH / EPDCCH with an uplink DCI format in a UE specific search space.

Value of CSI request field	Description
'00'	No aperiodic CSI report is triggered
'01'	Aperiodic CSI report is triggered for a set of CSI process (es) configured by higher layers for serving cell c
'10'	Aperiodic CSI report is triggered for a 1 st set of CSI process (es) configured by higher layers
'11'	Aperiodic CSI report is triggered for a 2 nd set of CSI process (es) configured by higher layers

In the table above, for which CSI cell (s) the aperiodic CSI reporting is triggered by CSI request field '01', CSI request field '10' and / or CSI request field '11', the higher layer signal (e.g. RRC Signal). When a CSI process is set in a serving cell by a higher layer, it is set whether aperiodic CSI reporting is triggered by a CSI request field '01', a CSI request field '10', and a CSI request field '11' for each CSI process. do. The trigger 01 for the CSI process indicates whether the corresponding CSI process is triggered by the CSI request field set to '01', and the trigger 10 indicates whether the corresponding CSI process is triggered by the CSI request field set to '10'. The trigger 11 indicates whether the corresponding CSI process is triggered by the CSI request field set to '11'. Depending on trigger 01, trigger 10, and trigger 11 for the CSI process, the CSI process may trigger aperiodic CSI reporting by both CSI request field '01', CSI request field '10', and CSI request field '11'. In either case, aperiodic CSI reporting may not be triggered by any of them, and only a part may trigger aperiodic CSI reporting.

The upper layer signal includes an 8-bit bitmap indicating a cell (s) to be triggered by the CSI request field '10' and an 8-bit bitmap indicating a cell (s) to be triggered by the CSI request field '11'. It may include. In each bitmap, bit 0, which is the lowest bit, to bit 7, which is the highest bit, correspond one-to-one to cells with a serving cell index of 0 (that is, Pcell) to cells with a serving cell index of 7. A cell corresponding to a bit set to 1 in the bitmap for the CSI request field '10' means a cell in which an aperiodic CSI report is triggered by the CSI request field value '10', and a cell corresponding to a bit set to 0 Denotes a cell in which aperiodic CSI reporting is not triggered by the CSI request field value '10'. A cell corresponding to a bit set to 1 in the bitmap for the CSI request field '11' means a cell in which an aperiodic CSI report is triggered by the CSI request field value '11', and a cell corresponding to a bit set to 0 Denotes a cell in which aperiodic CSI reporting is not triggered by the CSI request field value '11'.

7 to 9 illustrate examples of physically mapping a PUCCH format to PUCCH resources.

7 illustrates a slot level structure of a PUCCH format. In particular, FIG. 7 shows the structures of PUCCH formats 1a and 1b in the case of a normal cyclic prefix.

In PUCCH formats 1a and 1b, control information having the same content is repeated in a slot unit in a subframe. In each UE, the ACK / NACK signal has different cyclic shift (CS) (frequency domain codes) and orthogonal cover sequences (OCCs) of a computer-generated constant amplitude zero auto correlation (CG-CAZAC) sequence. (also called a cover code) (time domain spreading code). The OC sequence includes, for example, Walsh / DFT orthogonal code. If the number of CSs is six and the number of OC sequences is three, a total of 18 UEs may be multiplexed in the same physical resource block (PRB) based on a single antenna. The orthogonal sequence [w (0) w (1) w (2) w (3)] can be applied in any time domain (after FFT modulation) or in any frequency domain (before FFT modulation).

For SR and persistent scheduling, PUCCH resources composed of CS, OC sequence and Physical Resource Block (PRB) may be given to the UE through RRC (Radio Resource Control). For dynamic ACK / NACK and non-persistent scheduling, PUCCH resources may be implicitly given to the UE by the lowest CCE (Control Channel Element) index of the PDCCH corresponding to the PDSCH. .

8 shows an example of transmitting channel state information using a PUCCH format 2 / 2a / 2b in a UL slot having a regular CP.

Referring to FIG. 8, in the case of a normal CP, one UL subframe includes 10 OFDM symbols except for a symbol carrying a UL reference signal (RS). The channel state information is coded into 10 transmission symbols (also called complex modulation symbols) through block coding. The 10 transmission symbols are respectively mapped to the 10 OFDM symbols and transmitted to the eNB.

9 illustrates a PUCCH format based on block-spreading.

The block-spreading technique transmits a symbol sequence by time-domain spreading by an orthogonal cover code (OCC) (also called an orthogonal sequence). According to the block-spreading technique, control signals of several UEs may be multiplexed on the same RB and transmitted to the eNB by the OCC. In PUCCH format 2, one symbol sequence is transmitted over time-domain, but UCIs of UEs are multiplexed using cyclic shift (CCS) of a CAZAC sequence and transmitted to an eNB. On the other hand, in the case of a block-spread based new PUCCH format (hereinafter, PUCCH format 3), one symbol sequence is transmitted across a frequency-domain, where UCIs of UEs use OCC based time-domain spreading of UEs. UCIs are multiplexed and sent to the eNB. For example, referring to FIG. 9, one symbol sequence is spread by an OCC of length-5 (ie SF = 5) and mapped to five SC-FDMA symbols. In FIG. 9, a case in which a total of two RS symbols are used during one slot is illustrated, but three RS symbols are used and an OCC of SF = 4 may be used for spreading a symbol sequence and UE multiplexing. Here, the RS symbol may be generated from a CAZAC sequence having a specific cyclic shift, and may be transmitted from the UE to the eNB in a specific OCC applied / multiplied form to a plurality of RS symbols in the time domain. In FIG. 9, the Fast Fourier Transform (FFT) may be applied before the OCC, or the Discrete Fourier Transform (DFT) may be applied instead of the FFT.

For convenience of description, this channel coding based multiple ACK / NACK transmission scheme using PUCCH format 2 or PUCCH format 3 is referred to as a "multi-bit ACK / NACK coding" transmission method. This method generates an ACK generated by channel coding ACK / NACK or DTX information (meaning that a PDCCH cannot be received / detected) for PDSCH (s) of multiple DL CCs, that is, PDSCH (s) transmitted on multiple DL CCs. / NACK This indicates a method of transmitting a coded block. For example, if a UE operates in a single user MIMO (SU-MIMO) mode in a DL CC and receives two codewords (CW), ACK / ACK, ACK / NACK, NACK / ACK, One of a total of four feedback states of NACK / NACK may be transmitted, or one of a maximum of five feedback states including up to DTX may be transmitted. In addition, if the UE receives a single CW, there may be up to three feedback states of ACK, NACK, and DTX (if the NACK is treated the same as DTX, two feedback states of ACK, NACK / DTX May be). Thus, to be a maximum of 5 DL CC laminated to the UE, if operating in SU-MIMO mode for all CC may have up to ⁵⁵ of the transferable feedback state, ACK / NACK payload (payload) size to represent this, a total of 12 Bit. If, if the same handle DTX and NACK the number of feedback state is a dog 4 ^5, ACK / NACK payload size for representing this is a total of 10 bits.

As illustrated in FIG. 7 and FIG. 9, the UCI carried by one PUCCH may have a different size and use depending on the PUCCH format, and may vary in size depending on a coding rate. The following table illustrates the mapping relationship between the PUCCH format and UCI.

For example, the following PUCCH format may be defined.

PUCCH format	Modulation scheme	Number of bits per subframe	Usage	Etc.
One	N / A	N / A (exist or absent)	SR (Scheduling Request)
1a	BPSK	One	ACK / NACK orSR + ACK / NACK	One codeword
1b
QPSK	2	ACK / NACK orSR + ACK / NACK		Two codeword
2	QPSK	20	CQI / PMI / RI	Joint coding ACK / NACK (extended CP)
2a	QPSK + BPSK	21	CQI / PMI / RI + ACK / NACK	Normal CP only
2b	QPSK + QPSK	22	CQI / PMI / RI + ACK / NACK	Normal CP only
3	QPSK	48	ACK / NACK orSR + ACK / NACK orCQI / PMI / RI + ACK / NACK

Referring to the above table, the PUCCH format 1 series is mainly used to transmit ACK / NACK information, and the PUCCH format 2 series is mainly used to carry channel state information (CSI) such as CQI / PMI / RI. In particular, the PUCCH format 3 series is mainly used to transmit ACK / NACK information.

The UE is allocated a PUCCH resource for transmission of UCI from the eNB by a higher layer signal or a dynamic control signal or an implicit method. The physical resources used for the PUCCH depend on two parameters given by higher layers, N ⁽²⁾ _RB and N ⁽¹⁾ _cs . The variable N ⁽²⁾ _RB ≧ 0 represents the bandwidth available for PUCCH format 2 / 2a / 2b transmission in each slot and is expressed as N ^RB _sc integer multiples. Variable N ⁽¹⁾ _cs is the number of cyclic shifts (CS) used for PUCCH format 1 / 1a / 1b in the resource block used for mixing of formats 1 / 1a / 1b and 2 / 2a / 2b. Indicates. The value of N ⁽¹⁾ _cs becomes an integer multiple of Δ ^PUCCH _shift within the range of {0, 1, ..., 7}. Δ ^PUCCH _shift is provided by a higher layer. If N ⁽¹⁾ _cs = 0, there are no mixed resource blocks, and at most one resource block in each slot supports mixing of formats 1 / 1a / 1b and 2 / 2a / 2b. The resources used for transmission of PUCCH formats 1 / 1a / 1b, 2 / 2a / 2b, and 3 by antenna port p are non-negative integer indexes n ^{(1, p)} _PUCCH , n ^{(2, p)} _PUCCH < N ⁽²⁾ _RB N ^RB _sc + ceil ( N ⁽¹⁾ _cs / 8). ( N ^RB _sc - N ⁽¹⁾ _cs -2), and n ^{(3, p)} _PUCCH , respectively.

Specifically, according to a specific rule defined for each PUCCH format, an orthogonal sequence and / or cyclic shift to be applied to a corresponding UCI is determined from a PUCCH resource index, and resource indexes of two resource blocks in a subframe to which a PUCCH is mapped are given. For example, a PRB for transmission of a PUCCH in slot n _s is given as follows.

In Equation 1, the variable m depends on the PUCCH format, and is given to the PUCCH format 1 / 1a / 1b, the PUCCH format 2 / 2a / 2b, and the PUCCH format 3 by Equation 2, Equation 3, and Equation 4, respectively.

In Equation 2, n ^{(1, p)} _PUCCH is a PUCCH resource index of the antenna port p for the PUCCH format 1 / 1a / 1b, in the case of ACK / NACK PUCCH, the first CCE index of the PDCCH carrying the scheduling information of the PDSCH This is an implicit value.

n ⁽²⁾ _PUCCH is a PUCCH resource index of antenna port p for PUCCH format 2 / 2a / 2b, and is a value transmitted from eNB to UE by higher layer signaling.

n ⁽³⁾ _PUCCH is a PUCCH resource index of antenna port p for PUCCH format 2 / 2a / 2b, and is a value transmitted from eNB to UE by higher layer signaling. N ^PUCCH _{SF, 0} represents a spreading factor (SF) for the first slot of a subframe. N ^PUCCH for all within two slot sub-frame using a common PUCCH Format 3 _{SF, 0} to 5, and, N ^PUCCH for the first slot and the second slot from using a reduced PUCCH Format 3 sub-frames _{SF, 0} Are 5 and 4, respectively.

Referring to Equation 2, PUCCH resources for ACK / NACK is not allocated to each UE in advance, a plurality of PUCCH resources are used by each of the plurality of UEs in the cell divided at each time point. Specifically, the PUCCH resource used by the UE to transmit ACK / NACK is dynamically determined based on a PDCCH carrying scheduling information for a PDSCH carrying corresponding downlink data or a PDCCH indicating SPS release. The entire region in which the PDCCH is transmitted in each DL subframe consists of a plurality of control channel elements (CCEs), and the PDCCH transmitted to the UE consists of one or more CCEs. The UE transmits ACK / NACK through a PUCCH resource linked to a specific CCE (for example, the lowest index CCE) among the CCEs constituting the PDCCH received by the UE.

Each PUCCH resource index corresponds to a PUCCH resource for ACK / NACK. For example, assuming that scheduling information for a PDSCH is transmitted to a UE through a PDCCH configured with 4 to 6 CCEs, and the 4 CCE is linked to a PUCCH resource index 4, the UE configures the PDCCH 4 times. The ACK / NACK for the PDSCH is transmitted to the eNB through the PUCCH resource 4 corresponding to the CCE. Specifically, the PUCCH resource index for transmission by two antenna ports p ₀ and p ₁ in 3GPP LTE (-A) system is determined as follows.

Here, n ^{(1, p = p0)} _PUCCH represents an index (ie, number) of the ACK / NACK PUCCH resource to be used by antenna port p ₀ , and n ^{(1, p = p1)} _PUCCH is an ACK to be used by antenna port p ₁ / NACK represents a PUCCH resource index, N ⁽¹⁾ _PUCCH represents a signaling value received from a higher layer. n _CCE corresponds to the smallest value among the CCE indexes used for PDCCH transmission. For example, when the CCE aggregation level is 2 or more, the first CCE index among the indexes of the plurality of CCEs aggregated for PDCCH transmission is used for determining the ACK / NACK PUCCH resource. n ⁽¹⁾ a CS (Cyclic Shift), OC ( Orthogonal Code) and PRB for PUCCH format is obtained from the _PUCCH.

When PUCCH format 3 is configured for ACK / NACK transmission, a specific PUCCH format 3 resource index among the plurality of PUCCH format 3 resource indexes ( n ⁽³⁾ _PUCCH ) allocated by a higher layer (eg, RRC) is a DL grant. It may be indicated by an ACK / NACK Resource Indicator (ARI) value of the PDCCH (explicit PUCCH resource). The ARI is transmitted through the TPC field of the PDCCH scheduling the PDSCH of the Scell. n ⁽³⁾ and an OC PRB for PUCCH Format 3 is obtained from the _PUCCH.

Meanwhile, even in the case of EPDCCH-based scheduling, the ACK / NACK transmission resource for the DL data scheduled by the DL grant EPDCCH has a specific ECCE index (eg, a minimum ECCE index) constituting the DL grant EPDCCH or a specific offset value added thereto. It may be determined as a PUCCH resource linked to the ECCE index. In addition, the ACK / NACK feedback transmission resource may be determined as a PUCCH resource linked to a specific ECCE index (eg, a minimum ECCE index) constituting a DL grant EPDCCH or a PUCCH resource added with a specific offset value. Here, the specific offset value may be determined by a value directly signaled through an ACK / NACK Resource Offset (ARO) field in the DL grant EPDCCH and / or a value designated as dedicated for each antenna port. Specifically, the information signaled through the TPC field and the ARO field in the DL grant EPDCCH according to the frame structure type (eg, FDD or TDD) and ACK / NACK feedback transmission scheme (eg, PUCCH format 3 or channel selection) is as follows. Can be configured. For convenience, a TPC command for PUCCH power control is a "TPC value", an offset value added when the implicit PUCCH index is determined is an "ARO value", a plurality of PUCCH format 3 indexes assigned to RRC or a plurality of PUCCH format 1 indexes (multiple PUCCHs). An ARI indicating a specific one of format 1 index groups) is defined as an "ARI value". In addition, a fixed value (eg, '0') that is inserted without any information (for a purpose such as a virtual CRC) is defined as a "fixed value".

(ACK / NACK) determined dynamically (ie, implicitly) on the Pcell in the UL subframe corresponding to the ACK / NACK transmission timing for the DL subframe by detection of PDCCH / EPDCCH on the Pcell in the DL subframe The remaining PUCCH resource (s) for the SR, ACK / NACK and / or CSI except the PUCCH resource (s) are set by the higher layer.

 On the other hand, not only the merging of multiple CCs having the same UL-DL subframe configuration but also the merging of multiple CCs having different UL-DL subframe configuration is possible. For example, merging of multiple CCs with different UL-DL subframe settings is merging of multiple CCs configured with different UL-DL configurations (referred to as different TDD CAs for convenience), merging of TDD CCs and FDD CCs. It includes.

Cross-CC scheduling may be supported even when multiple CCs having different subframe configurations are merged. In this case, the HARQ timing set in each of the scheduling CC and the scheduled CC may be different. Accordingly, in order to perform UL grant and / or PHICH transmission for the scheduling CC UL SF and the UL data transmitted through the scheduling CC UL SF that is cross-CC scheduled through the scheduling CC, the same for each CC, Alternatively, consider applying different HARQ timings (set in a specific UL-DL configuration) or applying HARQ timings set in a specific UL-DL configuration to all CCs (ie, PCC (or scheduling CC) / SCC) in common. have. Specific UL-DL settings (hereinafter referred to as Reference Configurations (Ref-Cfg)) are either UL-DL configurations (MCC-Cfg) set in the PCC (or scheduling CC) or UL-DL configurations (SCC-Cfg) set in the SCC. It may be determined the same as or other UL-DL configuration. Here, the UL grant or PHICH timing may mean a DL subframe configured to transmit / receive a UL grant for scheduling UL data of a specific UL subframe and a PHICH for corresponding UL data transmission, or may mean a timing relationship thereof. Can be. Specifically, applying the UL grant or PHICH timing set in a specific CC (ie, Ref-CC) or a specific Ref-cfg means that a parameter value corresponding to UL-is set (UD-Cfg) or a specific UD-cfg of a specific CC is applied. This may mean using.

On the other hand, if the TDD PCell-FDD SCell CA applies the PDCCH / PDSCH-to-ACK / NACK timing (eg 4 ms) of the existing FDD cell to the PDSCH of the FDD cell as it is, the TDD PCell is DL SF in the ACK / NACK transmission timing. If defined as ACK / NACK can not be transmitted. Therefore, new DL HARQ timing may be applied instead of the PDCCH / PDSCH-to-ACK / NACK timing defined in the existing FDD cell. Likewise, the UL HARQ timing may apply the new HARQ timing. For example, there may be the following DL HARQ timing.

1) DL HARQ timing for TDD Scell in case of FDD Pcell (PDSCH to HARQ-ACK timing)

A. Self-Scheduling Case: Follow the DL HARQ timing of FDD Pcell.

B. Cross-carrier scheduling case: follows the DL HARQ timing of the FDD Pcell.

2) DL HARQ timing for FDD Scell in case of TDD Pcell (PDSCH to HARQ-ACK timing)

A. Self-Scheduling Case

i. Option 1: For each TDD Pcell U / D configuration, additional new timings (or more DL subframes than those defined in the TDD Pcell) for DL subframes where DL HARQ timing is not defined in TDD Pcell timing + TDD Pcell timing. New timings for each TDD Pcell U / D configuration to address them.

ii. Option 2: Follow the defined (or set) reference U / D settings for the FDD Scell. The reference U / D setting (configurable) depends on the U / D setting of the TDD Pcell. (New timing can be added to the reference U / D configuration above to support more DL subframes.)

B. Cross-carrier scheduling case: Same options as the self-scheduling case (option 1 and option 2), or else only follow the TDD Pcell timing.

In the future system after LTE, a method of operating while reconfiguring / changing a UL / DL SF direction for the purpose of enhanced interference mitigation and traffic adaptation (eIMTA) in a TDD situation has been considered. To this end, the basic UL-DL configuration (UD-cfg) of the TDD cell (or CC) is (semi-) statically configured using higher layer signaling (eg, SIB), and then the operation of the corresponding cell (or CC) is performed. A method of dynamically reconfiguring / modifying UD-cfg using lower layer signaling (eg, L1 (Layer1) signaling (eg, PDCCH)) has been considered. For convenience, the base UD-cfg is called SIB-cfg, and the operational UD-cfg is called actual-cfg. Subframe configuration according to UD-cfg is set based on Table 1. In addition, if DL SF, UL SF, and special SF are D, U, and S, respectively, D => U (or S) resetting takes into account existing (legacy) DL reception / measurement using CRS in the corresponding D. May not be easy or may cause deterioration. On the other hand, in the case of U (or S) => D reconfiguration, the base station may provide additional DL resources to the eIMTA UE by not intentionally scheduling / configuring UL signals that may be transmitted from the legacy UE through the corresponding U.

In view of this, the actual-cfg may be selectively determined only among UD-cfg (including SIB-cfg) including all D's on the SIB-cfg. That is, the UD-cfg in which all Ds are placed in the D position on the SIB-cfg may be determined as actual-cfg, but the UD-cfg in which the U is disposed in the D position in the SIB-cfg cannot be determined as the actual-cfg. Meanwhile, in eIMTA, a reference UD-cfg (hereinafter, D-ref-cfg) is separately set by a higher layer (signaling) to set HARQ timing (eg, HARQ-ACK feedback transmission timing) for DL scheduling. Can be. In consideration of this, the actual-cfg may be selectively determined only among UD-cfg (including D-ref-cfg) including all U on the D-ref-cfg. Therefore, the UD-cfg in which D is placed at the U position on the D-ref-cfg cannot be determined as the actual-cfg.

Thus, D-ref-cfg may be set to UD-cfg including all Ds on possible actual-cfg candidates, and SIB-cfg may be set to UD-cfg including all U on possible actual-cfg candidates. That is, D-ref-cfg may be set to D superset UD-cfg for possible actual-cfg candidates, and SIB-cfg may be set to U superset UD-cfg for possible actual-cfg candidates. . A reference UD-cfg (hereinafter, U-ref-cfg) of HARQ timing (eg, UG / PUSCH / PHICH transmission timing) for UL scheduling may be set to SIB-cfg. Accordingly, U on D-ref-cfg may be considered fixed U and D on SIB-cfg may be considered fixed D. Thus, only SF, which is D in D-ref-cfg and U in SIB-cfg, can be considered as flexible U, which can be reset / changed as U => D. Flexible U can be reset / changed to U => D by actual-cfg.

That is, after SIB-cfg / D-ref-cfg is set by higher layer (signaling), one of the UD-cfg (s) that includes all D on SIB-cfg and all U on D-ref-cfg Can be set to actual-cfg by L1 signaling.

In the FDD system, the eIMTA may be applied by resetting some UL SFs on the UL carrier to DL SF (and / or special SF) (hereinafter, referred to as FDD eIMTA). For example, a method of operating while reconfiguring / modifying UL SF on a UL carrier (dynamically) in accordance with a TDD UL-DL configuration may be considered.

A plurality of UCIs, a plurality of PUCCHs or a plurality of PUSCHs may collide in one subframe. Priority for uplink signal transmission is determined because of limitations of the UCI payload that can be transmitted in a single uplink channel and the fact that one UE is not allowed to simultaneously transmit a plurality of PUCCHs through a Pcell. Only high priority signal (s) are transmitted in that subframe and low priority signal (s) are dropped in that subframe.

The following table illustrates CSI information according to a PUCCH report type, a mode state, and payloads (bits per bandwidth part (BP), bits / BP) according to a PUCCH report mode.

PUCCH Reporting Type	Reported	Mode state	PUCCH Reporting Modes
			Mode1-1	Mode2-1	Mode1-0	Mode2-0
One	Sub-bandCQI	RI = 1	NA	4 + L	NA	4 + L
		RI> 1	NA	7 + L	NA	4 + L
1a	Sub-band CQI / second PMI	8 antenna ports RI = 1	NA	8 + L	NA	NA
		8 antenna ports 1 <RI <5	NA	9 + L	NA	NA
		8 antenna ports RI> 4	NA	7 + L	NA	NA
		4 antenna ports RI = 1	NA	8 + L	NA	NA
		4 antenna ports 1 <RI≤4	NA	9 + L	NA	NA
2	WidebandCQI / PMI	2 antenna ports RI = 1	6	6	NA	NA
		4 antenna ports RI = 1	8	8	NA	NA
		2 antenna ports RI> 1	8	8	NA	NA
		4 antenna ports RI> 1	11	11	NA	NA
2a	Widebandfirst PMI	8 antenna ports RI <3	NA	4	NA	NA
		8 antenna ports 2 <RI <8	NA	2	NA	NA
		8 antenna ports RI = 8	NA	0	NA	NA
		4 antenna ports 1≤RI≤2	NA	4	NA	NA
		4 antenna ports 2≤RI≤4	NA	NA	NA	NA
2b	Wideband CQI / second PMI	8 antenna ports RI = 1	8	8	NA	NA
		8 antenna ports 1 <RI <4	11	11	NA	NA
		8 antenna ports RI = 4	10	10	NA	NA
		8 antenna ports RI> 4	7	7	NA	NA
		4 antenna ports RI = 1	8	8	NA	NA
		4 antenna port 1 <RI≤4	11	11	NA	NA
2c	Wideband CQI / first PMI / second PMI	8 antenna ports RI = 1	8	NA	NA	NA
		8 antenna ports 1 <RI≤4	11	NA	NA	NA
		8 antenna ports 4 <RI≤7	9	NA	NA	NA
		8 antenna ports RI = 8	7	NA	NA	NA
		4 antenna ports RI = 1	8	NA	NA	NA
		4 antenna port 1 <RI≤4	11	NA	NA	NA
3	RI	2/4 antenna ports, 2-layer spatial multiplexing	One	One	One	One
		8 antenna ports, 2-layer spatial multiplexing	One	NA	NA	NA
		4 antenna ports, 4-layer spatial multiplexing	2	2	2	2
		8 antenna ports, 4-layer spatial multiplexing	2	NA	NA	NA
		8-layer spatial multiplexing	3	NA	NA	NA
4	Wideband CQI	RI = 1 or RI> 1	NA	NA	4	4
5	RI / first PMI	8 antenna ports, 2-layer spatial multiplexing	4	NA	NA	NA
		8 antenna ports, 4 and 8-layer spatial multiplexing	5
		4 antenna ports, 2-layer spatial multiplexing	4
		4 antenna ports, 4-layer spatial multiplexing	5
6	RI / PTI	8 antenna ports, 2-layer spatial multiplexing	NA	2	NA	NA
		8 antenna ports, 4-layer spatial multiplexing	NA	3	NA	NA
		8 antenna ports, 8-layer spatial multiplexing	NA	4	NA	NA
		4 antenna ports, 2-layer spatial multiplexing	NA	2	NA	NA
		4 antenna ports, 4-layer spatial multiplexing	NA	3	NA	NA

Referring to the above table, when a CSI report of PUCCH report type 3, 5 or 6 of one serving cell collides with PUCCH report type 1, 1a, 2, 2a, 2b, 2c or 4 of the same serving cell, that is, If the report timing is the same subframe, the latter CSI report of the PUCCH report type has a low priority and is dropped at the corresponding report timing. For the UE set to transmission mode 10, if the CSI reports of the same serving cell having the same priority PUCCH report type collide with each other and the CSI reports correspond to different CSI processes, the CSI process having the lowest CSI process ID is selected. All CSI reports corresponding to the excluded CSI processes are dropped. Same serving with PUCCH report type of equal priority for UE set to transmission mode 1-9 and set to CSI subframe set C _{CSI, 0} and CSI subframe set C _{CSI, 1} by higher layer signal for serving cell In case of collision between CSI reports of a cell, the CSI report corresponding to the CSI subframe set C _{CSI, 1} is dropped. The same serving cell with the PUCCH report type of the same priority, for a UE set to transmission mode 10 and set as CSI subframe set C _{CSI, 0} and CSI subframe set C _{CSI, 1} by higher layer signal for the serving cell If the CSI reports of C collisions and the CSI reports correspond to CSI processes with the same CSI-process ID, then the CSI report corresponding to the SI subframe set C _{CSI, 1} is dropped. If the UE is configured with more than one serving cells, the UE transmits CSI report of only one serving cell in a given subframe. For a given subframe, if the CSI report of PUCCH report type 3, 5, 6 or 2a of one serving cell collides with the CSI report of PUCCH report type 1, 1a, 2, 2b, 2c or 4 of another serving cell, the latter The CSI report of has a low priority and is dropped in the subframe (ie, corresponding transmission timing). For a given subframe, if a CSI report of PUCCH report type 2, 2b, 2c or 4 of one serving cell collides with a CSI report of PUCCH report type 1 or 1a of another serving cell, the latter CSI report has a lower priority. And drop in the subframe (ie, corresponding transmission timing). For serving cells in which UE is set to transmission mode 1-9 in a given subframe, if the CSI reports of other serving cells having the same priority PUCCH report type collide with each other, serving except the serving cell having the lowest serving cell index All CSI reports for the cells are dropped. For serving cells in which a UE is set to transmission mode 10 in a given subframe, CSI reports of other serving cells having the same priority PUCCH report type collide with each other and the CSI reports have CSI processes with the same CSI-process ID. If corresponding, all CSI reports for serving cells except the serving cell with the lowest serving cell index are dropped. For serving cells in which a UE is set to transmission mode 10 in a given subframe, CSI reports of other serving cells having the same priority PUCCH report type collide with each other and the CSI reports are sent to CSI processes with different CSI-process ID. If corresponding, CSI reports of all serving cells except the serving cell with CSI reports corresponding to the CSI process with the lowest CSI-process ID are dropped. In a given subframe, the CSI report of the serving cell in which the UE is set to transmission mode 1-9 and the CSI report (s) corresponding to the CSI process (s) of another serving cell in which the UE is set to transmission mode 10 collide, and the serving If the CSI reports of cells are of the same priority PUCCH report type, then the CSI report (s) corresponding to the CSI process (s) with CSI process ID> 1 of the other serving cell are dropped. In a given subframe, the CSI report of the serving cell in which the UE is set to transmission mode 1-9 and the CSI report corresponding to the CSI process of CSI process ID = 1 of another serving cell in which the UE is set to transmission mode 10 are collided, and If the CSI reports of the serving cells are of the same priority PUCCH report type, the CSI report of the serving cell with the highest serving cell index is dropped.

If the UE is not configured for simultaneous PUSCH and PUCCH transmission, or if the UE is configured for simultaneous PUSCH and PUCCH transmission but not timing to transmit PUSCH, CSI is dropped if CSI and positive SR collide in the same subframe .

If the periodic CSI report and the HARQ-ACK for the UE collide in the same subframe without the PUSCH, if the periodic CSI report and the HARQ-ACK cannot be transmitted in a single uplink channel (e.g., provided by a higher layer) If the simultaneous ACK / NACK and CQI parameters are set to false), the periodic CSI report is dropped. If the periodic CSI reporting and HARQ-ACK collide in the same subframe without PUSCH for a UE configured as a single serving cell and not configured as PUCCH format 3, the simultaneous ACK / NACK and CQI parameters provided by the higher layer are true. If set to, the periodic CSI report is multiplexed with HARQ-ACK on PUCCH, otherwise the CSI is dropped.

If the UE is not configured for simultaneous PUSCH and PUCCH transmission, the UE transmits the periodic CSI report on the PUCCH in a subframe without PUSCH assignment and on the PUSCH of the serving cell with the lowest serving cell index in the subframe with PUSCH assignment. Send the periodic CSI report. If the periodic CSI report and the aperiodic CSI report occur in the same subframe, the UE transmits only the aperiodic CSI report in the subframe.

If SR and ACK / NACK collide, SR and ACK / NACK may be multiplexed and transmitted together.

As more communication devices demand larger communication capacities, efficient utilization of limited frequency bands becomes an increasingly important requirement in future wireless communication systems. Cellular communication systems, such as 3GPP LTE / LTE-A systems, also utilize unlicensed bands, such as the 2.4GHz band used by existing WiFi systems, or unlicensed bands, such as the emerging 5GHz band, for traffic offloading. How to do this is under consideration.

Basically, the unlicensed band assumes a method of wireless transmission and reception through competition between communication nodes, so that channel communication is performed before each communication node transmits a signal to confirm that other communication nodes do not transmit a signal. Is required. This is called a clear channel assessment (CCA), and an eNB or a UE of an LTE system may also need to perform CCA for signal transmission in an unlicensed band (hereinafter, referred to as LTE-U band). In addition, when the eNB or the UE of the LTE system transmits a signal, other communication nodes such as WiFi should also perform CCA to not cause interference. For example, in the WiFi standard (e.g., 801.11ac), the CCA threshold is defined as -62dBm for non-WiFi signals and -82dBm for WiFi signals, which means that either STA or AP, For example, if a signal other than WiFi is received at power of -62dBm or more, it means that no signal transmission is performed so as not to cause interference. Characteristically, in a WiFi system, an STA or an AP may perform CCA and perform signal transmission if it does not detect a signal above the CCA threshold for 4us or more.

In a CA situation of the LTE-A band and the LTE-U band, the eNB may transmit a signal to the UE or the UE may transmit a signal to the eNB. In the following description, for the convenience of explanation of the proposed scheme, it is assumed that the UE is configured to perform wireless communication through two component carriers (CC) in each of the licensed band and the unlicensed band. Here, as an example, the carrier of the licensed band may be configured as a primary component carrier and the carrier of an unlicensed band may be configured as a secondary component carrier. However, embodiments of the present invention can be extended and applied even in a situation where a plurality of licensed bands and a plurality of unlicensed bands are used as a carrier aggregation technique, and can also be applied to signal transmission and reception between an eNB and a UE using only an unlicensed band. . In addition, embodiments of the present invention can be extended and applied to not only 3GPP LTE / LTE-A system but also other system characteristics.

Hereinafter, for convenience of description, a cell set in a licensed band for 3GPP LTE / LTE-A and operating in a 3GPP LTE / LTE-A scheme is referred to as an Lcell, and is set in an unlicensed band operated in an LTE-U scheme. A cell operating in the -U manner is called a Ucell.

In order for the eNB and the UE to communicate in the LTE-U band, first, because the corresponding band is an unlicensed spectrum, the band is allocated for a specific time interval through competition with other communication (eg, WiFi) systems unrelated to LTE / LTE-A. Must be able to seize / acquire Hereinafter, for convenience, a time period occupied / obtained for communication in the LTE-U band is referred to as a reserved resource period (RRP). There may be various ways to secure such RRP. Typically, other communication system devices, such as WiFi, send a specific reservation signal so that the radio channel is busy, or RS and / or data to continuously transmit a signal above a certain power level during RRP. It is possible to transmit a signal continuously.

RRP may be set by carrier detection by the eNB. If the eNB has previously determined the RRP to occupy the LTE-U band, it can inform the UE in advance so that the UE can maintain the communication transmit / receive link during the indicated RRP. In order to inform the UE of the RRP information, the corresponding RRP information may be delivered through another CC (eg, the LTE-A band) connected in the carrier aggregation form.

The RRP determination agent may vary depending on whether the DL transmission or the UL transmission. For example, RRP (DL RPP) for DL transmission may be determined by the eNB based on carrier detection by the eNB. UL RRP (UL RRP) for UL transmission may be determined by the eNB based on the carrier detection by the eNB and may be indicated to the UE. Alternatively, the UE may check or determine the UL RRP in units of subframes by checking the channel state before signal transmission, that is, through carrier detection by the UE itself.

In the cell used for the existing CA, that is, the Lcell, RS for channel synchronization or RS for channel measurement such as PSS / SSS / PBCH, CRS and / or CSI-RS appears periodically and continuously. In contrast, in the case of a Ucell, the eNB may set an RRP and transmit a channel measurement RS on the RRP only when the Ucell is idle. Thus, on the Ucell, synchronization / measurement RSs will appear aperiodically and / or discontinuously.

Meanwhile, in the case of the Lcell, the UE is configured to detect the RS (s) during the time period in which the Lcell is activated or to perform synchronization or measurement using the RS (s), but the RS (s) in the time interval in which the Lcell is inactive. ) Is not sent at all. The synchronization / measurement RSs are continuously transmitted regardless of the activation or deactivation of the Lcell, but the UE is configured to detect the synchronization / measurement RSs only during the activated time interval. In contrast, in the case of Ucell, the eNB transmits synchronization or measurement RS (s) only during the RRP, and the wireless communication medium during the non-RRP is occupied by other devices, so that the synchronization or measurement of the eNB is performed. RS (s) are in principle not transmitted during non-RRP.

As another example of the unlicensed band operation operating in a contention-based random access scheme, the eNB may first perform carrier detection (CS) before data transmission / reception. If the Scell checks whether the current channel state is busy or idle, and determines that it is idle, the eNB transmits a scheduling grant over the Pcell's PDCCH (ie, cross-carrier scheduling) or over the Scell's PDCCH. You can try to send / receive data. In this case, for example, an RRP configured of M consecutive subframes (SFs) may be set. Here, the eNB may inform the UE of the M values and the M SFs in advance through higher layer signaling (using a Pcell) or a physical control / data channel. The starting point of the RRP may be set periodically or semi-statically by higher layer signaling. Alternatively, when the RRP start point should be set to SF #n, the start point of the RRP may be designated through physical layer signaling in SF #n or SF # (n-k).

10 illustrates a subframe configuration of a reserved resource period (RRP).

In the RRP, the boundary of the subframe (s) constituting the RRP is configured to match the boundary of the subframe (s) set on the Pcell as shown in FIG. 10 (a), or FIG. 10 (b). As shown in FIG. 2), the configuration may be configured to support a form that does not match the boundary of the subframe (s) set on the Pcell.

As mentioned above, the LTE-U system operating based on competition through carrier sensing in the unlicensed band is available depending on the carrier detection result (eg, available for data transmission / scheduling purposes). ) Resource intervals can be secured / configured aperiodically. When the cell / carrier that operates in the LTE-U method is called a Ucell for convenience, and a resource section configured aperiodically on the Ucell is defined as RRP, the eNB identifies a UE configured with the Ucell when the RRP section is secured on the Ucell. As a target, we can consider the situation of scheduling data transmission only through the corresponding RRP interval.

 When a plurality of cells are configured in the UE, the LTE-A system commonly applies a timing advance (TA) value applicable to one specific cell (eg, PCC or Pcell) to the plurality of cells. However, Ucells and non-Ucells belonging to different frequency bands (ie, greatly spaced apart on a frequency) may be carrier aggregated, or propagation characteristics of the carrier aggregated Ucell and non-Ucell may be different. In addition, in the case of a specific cell, a situation may occur in which devices such as an RRH are disposed in a cell in order to expand coverage or to remove a coverage hole. In this case, when UL transmission is performed using a method in which one TA value is commonly applied to a plurality of carrier aggregated cells, it may seriously affect synchronization of UL signals transmitted on the plurality of cells.

The UE is configured as two cells (eg, PCell and SCell), and a UL signal may be transmitted by applying a different TA for each cell. For example, TA 1 may be applied to UL transmission of a PCell and TA 2 may be applied to UL transmission of a SCell. The transmission end time of the UL subframe / signal (eg, PUSCH, PUCCH, SRS, etc.) may be advanced by TA based on the reception end time of the DL subframe. Equivalently, the transmission start time of the UL subframe / signal (eg, PUSCH, PUCCH, SRS, etc.) may be advanced by TA based on the reception start time of the DL subframe.

Therefore, it may be considered to allocate TA independently per cell group / unit. Hereinafter, a group of cells using the same timing reference cell and the same TA value for cells set by a higher layer (eg, RRC) and configured with UL is referred to as a TA group (TA group, TAG). The TAG may include one or more cells CC. One TA may be commonly applied to the cell (s) in the TAG. The TAG may be classified into a primary TAG (PTAG) including a Pcell and a secondary TAG (STAG) including at least one serving cell with a UL set without including the Pcell. In the case of a PTAG to which a Pcell belongs, a TA determined based on the Pcell or adjusted through a random access procedure accompanying the Pcell may be applied to all cell (s) in the PTAG. On the other hand, in the case of an STAG that does not include a Pcell, that is, composed of only Scell (s), a TA determined based on a specific Scell in the STAG may be applied to all Scell (s) in the STAG. To this end, the random access procedure may be performed not only through the Pcell but also through the Scell. The random access procedure accompanying the Scell is a non-competitive random access procedure triggered using a PDCCH (i.e., PDCCH order) for the eNB to command the RACH preamble transmission, rather than a contention based scheme triggered by the UE. This can be done.

To date, LTE / LTE-A systems can support CAs for up to five cells / carriers / CCs (hereinafter collectively referred to as cells) for a single UE, and dual connectivity (DC) is established. Except for the case, the PUCCH carrying UCI (eg, HARQ-ACK, CSI, etc.) associated with the plurality of cells may be transmitted through only one Pcell. When configured as a master cell group (MCG) or secondary cell group (SCG), the UE in the RRC_connected state is configured as DC. Each serving cell of the UE belongs exclusively to the MCG or SCG. When the UE is configured as DC, it means that the UE is connected to two eNBs at the same time, and MCG is a cell managed by an eNB (hereinafter, eNB M) to which the UE first connects among the two eNBs. ), And the remaining SCG is composed of cell (s) managed by an eNB (hereinafter, referred to as eNB S) further connected after the UE connects to eNB M. After all, since the UE configured as DC is connected to two eNBs, that is, two schedulers, DL / UL scheduling, UCI transmission, etc. for MCG are performed to be limited to cells of MCG, and DL / UL scheduling for SCG, UCI transmission is performed limited to the cells of the SCG. Therefore, in the case of cross-carrier scheduling, if the scheduling cell belongs to the MCG, the scheduling cell of the scheduling cell also belongs to the MCG, and if the scheduling cell belongs to the SCG, the scheduling cell of the scheduling cell also belongs to the SCG, Cross-scheduling between the cells of and the cells of the SCG is not performed. In other words, the scheduling cell and the corresponding scheduled cell do not belong to another CG. In addition, a UE configured as DC has two Pcells, one for each eNB, UCI for MCG is transmitted through PUCCH on Pcell of MCG, and UCI for SCG is transmitted on PUCCH on Pcell of SCG, and UCI for MCG The UCI for the SCG or for the SCG cannot be transmitted in the MCG.

 Meanwhile, the next system may be considered to support CAs of five or more cells for one UE for a higher data rate. In this case, in order to reduce the UCI transmission frequency / size (by increasing the number of cells constituting the CA) and thereby reduce the PUCCH resource burden on the Pcell, PUCCH may also be performed through a specific Scell (hereinafter, Acell). (UCI through this) may be considered to enable the transmission. While the Pcell of the MCG and the Pcell of the SCG are controlled by independent schedulers, the Pcell and Acell according to the present invention are controlled by a single scheduler.

The present invention proposes a UCI transmission structure and method through PUCCH / PUSCH suitable for a case where PUCCH transmission through Acell is configured to be possible in a CA. Basically, if the entire CA is configured to enable transmission of HARQ-ACK PUCCH through Acell in a state in which two cell groups (CGs) are set as CG1 and CG2, HARQ- for CG1 (DL data reception through it) is set. In the case of a PUCCH carrying an ACK, a PUCCH carrying a HARQ-ACK for a CG2 may be transmitted through a corresponding Acell, where the Pcell may be included in the CG1 and the Acell may be included in the CG2. For convenience of description, embodiments of the present invention will be described taking the case where Pcell belongs to CG1 and Acell belongs to CG2 as an example. However, embodiments of the present invention may be similarly applied when Pcell belongs to CG2 and Acell belongs to CG1. . In addition, although a situation in which one Acell and two CGs are set for convenience of description, even if two or more Acells and three or more CGs are set, the proposed principle and operation of the present invention may be similarly applied.

The dynamic PUCCH resource on the Acell may be determined based on the lowest CCE index of the DL grant PDCCH or SPS release PDCCH transmitted on the Acell or the lowest CCE index of EPDCCH. Explicit PUCCH resources or explicit PUCCCH resource candidates on the Acell may be set by a signal to a higher layer. PUCCH resources actually used among the PUCCH resource candidates may be indicated by the ARI.

■ Scell UCI transmission cell selection method when PUCCH transmission is set

When PUCCH transmission is configured in Acell in CA, it may be considered to select a UCI transmission cell in the following manner for more flexible and efficient UCI transmission.

11 through 14 illustrate UCI transmission according to embodiments of the present invention.

Case 1) No UL channel transmission or only PUSCH transmission within one CG

If there are no UL channel transmissions (e.g., PUCCH or PUSCH) for all of the specific CGs or only PUSCH transmissions exist (at the same time, simultaneous transmission of multiple UCIs via different CGs is required), another CG (e.g., Simultaneous transmission of a plurality of PUCCHs through a PUCCH transmission cell belonging to the corresponding CG may be allowed. Simultaneous transmission hereinafter means that corresponding signals are transmitted in a single subframe.

For example, referring to FIG. 11 (a), through A / N (or CG1) through CG1 (with or without simultaneous transmission of ACK / NACK (hereinafter, A / N) and CSI over PUCCH) If there is no PUCCH or PUSCH transmission (ie, no PUCCH and no PUSCH) in the entire CG2 in the case where N transmission and CSI transmission are required at the same time, or only PUSCH transmission exists, A / (for CG1) Both PUCCH carrying N and PUCCH carrying CSI (for CG1) may be transmitted simultaneously over CG1 (eg, Pcell). As another example, referring to FIG. 11 (b), A / N transmission and CSI transmission are simultaneously required through CG1 (or CG1) while the simultaneous transmission of A / N and CSI over PUCCH is not set. In a situation where there is a PUCCH and PUSCH transmission in CG2 or a PUCCH transmission, the transmission of CSI (for CG1) is omitted / discarded (i.e., dropped) and one A / N carrying (for CG1) Only PUCCH may be transmitted through CG1 (eg, Pcell).

On the other hand, when SR transmission and CSI transmission are simultaneously required through CG1, an operation similar to the above examples may be applied. For example, in the above examples, a manner of replacing A / N with SR may be considered.

Case 2) Multiple UCIs in one CG having higher priority than UCIs in other CGs

When a plurality of UCIs (eg, A / N, CSI, and / or SR) requiring transmission through a specific CG have a higher priority than UCIs requiring transmission through another CG, the specific CG ( For example, simultaneous transmission of a plurality of PUCCHs through a PUCCH transmission cell belonging to the specific CG may be allowed.

For example, A / N transmission and CSI (i.e., CG1-CSI) transmission over CG1 (or CG1) with CG1 (with no simultaneous transmission of A / N and CSI set on PUCCH), CG2 If (CG2) CSI (i.e., CG2-CSI) transmissions are required at the same time, if CG1-CSI has a higher priority than CG2-CSI, then the transmission of CG2-CSI is dropped (CG1). The PUCCH carrying A / N and the PUCCH carrying CG1-CSI may be simultaneously transmitted through the CG1 (eg, Pcell). 12 (a) and 12 (b), there are A / N PUCCH and CSI PUCCH in which transmission is set on CG1 in a subframe, and PUCCH (high priority) in which transmission is set on CG2 in the same subframe. If is not present, unlike the existing system, A / N PUCCH and CSI PUCCH are simultaneously transmitted on the CG1 in the subframe. In FIG. 12, P1 and P2 mean priority, and it is assumed that CSI of P1 has higher priority than CSI of P2.

As another example, A / N and CSI (i.e., CG1-CSI) transmissions over CG1 (or CG1) with CG1 (with or without simultaneous transmission of A / N and CSI on PUCCH) set to CG2. If (CG2) CSI (i.e., CG2-CSI) transmissions are required at the same time, if CG1-CSI has a lower priority than CG2-CSI, then transmission of CG1-CSI is dropped and A / N The PUCCH carrying the CG1 (eg, Pcell) and the PUCCH carrying the CG2-CSI may be transmitted via the CG2 (eg, Acell). Referring to FIG. 12 (c), if there is an A / N PUCCH with transmission set on CG1 in a subframe and a CSI PUCCH having priority P2 and a CSI PUCCH having priority P1 with transmission set on CG2 in the same subframe, In this subframe, the A / N PUCCH is transmitted on the CG1 and the CSI having priority P1 is transmitted on the PUCCH of the CG2 at the same time. In the corresponding subframe, the CSI having priority P2 is dropped.

On the other hand, when SR transmission and CSI transmission are simultaneously required through CG1, an operation similar to the above examples may be applied. For example, in the above examples, a manner of replacing A / N with SR may be considered.

Case 3) collision of multiple UCIs within one CG

When simultaneous transmission of multiple UCIs is required through a specific CG (at the same time, there is no PUCCH or PUSCH transmission for all other CGs (ie, no PUCCH and no PUSCH), or only PUSCH transmission exists) A specific portion of the plurality of UCIs (eg, a UCI having a lower priority) may be transmitted through another CG. In FIG. 13, P1 and P2 indicate a priority, and P1 has a higher priority than P2. 13, if UCI with priority P1 and UCI with priority P2 configured for transmission in one CG occur in the same subframe, if the UCIs cannot be transmitted through a single PUCCH or PUSCH, UCI with priority P2 is transmitted on another CG.

For example, if no simultaneous transmission of A / N and CSI over PUCCH is set, and no PUCCH is sent to the entire CG2 in a situation where A / N transmission and CSI transmission are simultaneously required through CG1 (or CG1). Or if there is no PUSCH transmission (i.e. no PUCCH and no PUSCH) or only PUSCH transmission is present, the A / N (for CG1) via the PUCCH on CG1 (e.g. Pcell), CSI may be transmitted through PUCCH or PUSCH on CG2 (eg, Acell), respectively. In this case, the PUCCH resource on the CG2 used, for example, the corresponding CSI PUCCH resource on the CG2 may be preset by an upper layer signal (eg, an RRC signal). PUSCH resources on the CG2 used at this time may be allocated through the UL grant transmitted on a specific cell according to the self-CC scheduling configuration or cross-CC scheduling configuration.

As another example, there is no PUCCH or PUSCH transmission in the entire CG2 in a situation where aperiodic CSI (hereinafter referred to as a-CSI) transmission through CG1 (or to CG1) and periodic CSI (hereinafter referred to as p-CSI) transmission are simultaneously required. (I.e., no PUCCH, no PUSCH) or only PUSCH transmission, the a-CSI is via PUSCH on CG1 and the p-CSI is via PUCCH or PUSCH on CG2 (e.g., Acell). Each can be sent. If there is a UCI that needs to be transmitted from another CG, the UCI of the lower priority within the CG is dropped by prioritizing within each CG. In this case, even if a low priority UCI in one CG (eg, CG1) is higher than the highest priority UCI in another CG (eg, CG2), the UCI of CG1 may be dropped. Can be.

On the other hand, when SR transmission and CSI transmission are simultaneously required through CG1, an operation similar to the above examples may be applied. For example, in the above examples, a method of replacing A / N with SR may be considered.

Case 4) collision of multiple UCIs over CGs

If a plurality of UCIs (hereinafter, UCI-a) required to be transmitted through a specific CG has a higher priority than UCI (s) (hereinafter, UCI-b) required to be transmitted through another CG, the UCI- Certain portions of a (eg, UCIs with lower priorities) may be sent over other CGs. In FIG. 14, it is assumed that priority P1 is higher than priority P2 and priority P2 is higher than priority P3. Referring to FIGS. 14A and 14B, UCI with priority P1 and UCI with priority P2 having transmission set on CG1 may occur in the same subframe, and the UCIs may be transmitted on a single PUCCH or PUSCH. If there is no UCI of higher priority than P1 and P2 to be transmitted on the CG2 to be transmitted in the corresponding subframe, the UCI of the higher priority P1 is transmitted on the CG1 to which the original transmission was set and the lower priority. UCI of rank P2 is transmitted through PUCCH or PUSCH on CG2. Referring to FIG. 14 (b), UCIs having a lower priority than P1 and P2 to be transmitted on CG2 in the subframe are dropped. Referring to FIG. 14 (c), if the UCI having a higher priority than the UCIs configured for transmission in the CG1 is present in the CG2, the UCI (s) of the CG1 having a lower priority than the UCI of the CG2 are dropped in the corresponding subframe. .

For example, A / N transmission and CSI (hereinafter, CG1-CSI) transmission are required through CG1 (or CG1) without simultaneous transmission of A / N and CSI through PUCCH. If CG1-CSI has higher priority than CG2-CSI when CSI (or CG2-CSI) transmission is required through CG2 (or CG2) at the same time, transmission of CG2-CSI is dropped and (CG1 A / N may be transmitted through PUCCH on CG1 (eg, Pcell), and the CG1-CSI may be transmitted on PUCCH or PUSCH on CG2 (eg, Acell).

As another example, a-CSI transmission and p-CSI (hereinafter CG1-CSI) transmission are required through CG1 (or CG1) and p-CSI (or CG2-) through CG2 (or CG2). When CG) transmission is simultaneously required, when CG1-CSI has a higher priority than CG2-CSI, transmission of CG2-CSI is dropped and the a-CSI is transmitted through PUSCH on CG1, and the CG1-CSI is CG2 ( For example, it may be transmitted through PUCCH or PUSCH on Acell. Here, the PUCCH on the CG2 used for the transmission of the CG1-CSI may be a PUCCH resource set for transmission (without CG classification). The PUSCH on the CG2 used for the transmission of the CG1-CSI may be allocated on the CG2 through the UL grant transmitted on the specific cell according to the self / cross-CC scheduling configuration regardless of the UCI.

On the other hand, when SR transmission and CSI transmission are simultaneously required through CG1, an operation similar to the above examples may be applied. For example, in the above examples, a method of replacing A / N with SR may be considered.

In the above-described embodiments of Cases 1 to 4, the number of PUCCHs or UCIs transmitted simultaneously in one subframe may depend on the number of cell groups or the number of cells for PUCCH transmission (ie, Pcell and Acell).

■ UCI transmission method when cross-CC scheduling setting is allowed between CGs

When PUCCH transmission is configured on an Scell (that is, Acell) in a CA situation, an a-CSI request from an eNB and an a-CSI report from a UE may be basically performed for each CG. A cell set or a CSI process set configured as an a-CSI measurement target (via upper layer (e.g. RRC) signaling) may also be configured for each CG.

When cross-CC scheduling is set between CGs in a CA situation in which Acell PUCCH transmission is configured, a specific (scheduling) cell 1 and a (pic scheduling) cell 2 configured to be scheduled from the cell 1 may belong to different CGs. . For example, cell 1, which is a scheduling cell, may belong to CG1, and cell 2, which is a scheduled cell, may belong to CG2. At this time, a PUSCH on cell 2 is scheduled through UL grant DCI transmission on cell 1 and at the same time, through DCI. When a-CSI transmission is indicated, the a-CSI measurement / reporting cell (s) or CSI process (s) corresponding to the a-CSI request are configured in cell 2, which is a scheduled cell, and CG2 to which cell 2 belongs. It may be determined based on a-CSI measurement target cell (or CSI process) set. For example, a triggerXX that indicates whether a-CSI is triggered by the CSI request field value XX (where XX is 01, 10, 11) is configured / set only for cells (or CSI processes) within that CG. Can be. This method may be equally applied to a-CSI request / report and a-CSI measurement target cell (or CSI process) set configuration / configuration for each cell group in the absence of Scell PUCCH transmission setting. That is, in the state where Acell is not configured at all, the cells may be divided into cell groups for a-CSI measurement.

Meanwhile, in the case of the existing CA in which PUCCH transmission is performed only through one Pcell, scheduling cell 1 and scheduled cell 2 configured to be scheduled from cell 1 and UCI (eg, A / N) PUCCH for cell 2 are transmitted. It can be considered that all Pcells belong to the same CG. In this case, the HARQ-ACK transmission timing (or reference UL / DL setting for HARQ-ACK transmission timing determination) for DL data reception in the cell 2 is determined whether the cell 2 is configured to be cross-CC scheduled from another cell. It may be determined differently depending on whether or not. Hereinafter, the timing applied when Cell 2 is set to be scheduled by another cell is referred to as cross-HARQ timing, and the timing applied when Cell 2 is not set to be scheduled by another cell is called self-HARQ timing. .

Unlike the existing CA in which PUCCH transmission is performed only through one Pcell, when cross-CC scheduling is set between CGs in a CA where Acell PUCCH transmission is configured, scheduling cell 1 and scheduled cell 2 configured to be scheduled therefrom are While belonging to different CGs, a cell in which UCI (eg, A / N) PUCCH for cell 2 and cell 2 are transmitted may belong to the same CG. For example, cell 1, which is a scheduling cell, belongs to CG1, and cell 2, which is a scheduled cell, belongs to CG2, and a cell to which UCI (eg, A / N) PUCCH for cell 2 is transmitted is in CG2, which is the same CG as cell 2. Can belong. In this case, to reduce unnecessary DL scheduling restrictions due to inefficient HARQ-ACK timing setting / application,

Alt 1) whether or not cell 2 is configured to be cross-CC scheduled from a PUCCH transmission cell (i.e., Pcell or Acell) configured in CG2 to which cell 2 belongs, or

Alt 2) The corresponding HARQ-ACK timing may be determined differently according to whether cell 2 is set to be cross-CC scheduled from any cell belonging to the CG2.

For example, if there is a cross-CC scheduling configuration (based on Alt 1 or Alt 2) for cell 2, cross-HARQ timing is applied, and cross-CC (based on Alt 1 or Alt 2) for cell 2 If there is no scheduling configuration, self-HARQ timing may be applied. For example, in the case of Alt 1, if cell 2 belonging to CG2 is set to be scheduled from any cell (belonging to CG1 or CG2) other than the PUCCH transmission cell configured in CG2, cell 2 belonging to CG2 in Alt 2 Is set to be scheduled from any cell belonging to CG1), self-HARQ timing may be applied. In the case of the Alt 1 scheme, the same may be applied to a CA situation in which there is no Scell PUCCH transmission setting.

On the other hand, since the Acell also corresponds to one Scell from the perspective of the entire CA, a method of deactivating similarly to the general Scell may be considered. In this case, basically all cells belonging to the CG including the Acell may be simultaneously deactivated in a batch. In this case, when cross-CC scheduling between CGs is allowed, another CG (eg, CG2 scheduling cell) configured to be cross-CC scheduled from the deactivated Acell and a cell belonging to the CG (eg, CG2) including the same (hereinafter, CG2 scheduling cell). The cells in CG1) (hereinafter, CG1 scheduled cells) may also be deactivated together. In the case of such a CG1 scheduled cell, it can be activated only when both the Acell and CG2 scheduling are activated.

15 is a block diagram showing the components of the transmitter 10 and the receiver 20 for carrying out the present invention.

The transmitter 10 and the receiver 20 are radio frequency (RF) units 13 and 23 capable of transmitting or receiving radio signals carrying information and / or data, signals, messages, and the like, and in a wireless communication system. The device is operatively connected to components such as the memory 12 and 22, the RF unit 13 and 23, and the memory 12 and 22, which store various types of information related to communication, and controls the components. And a processor (11, 21) configured to control the memory (12, 22) and / or the RF unit (13, 23), respectively, to perform at least one of the embodiments of the invention described above.

The memories 12 and 22 may store a program for processing and controlling the processors 11 and 21, and may temporarily store input / output information. The memories 12 and 22 may be utilized as buffers.

The processors 11 and 21 typically control the overall operation of the various modules in the transmitter or receiver. In particular, the processors 11 and 21 may perform various control functions for carrying out the present invention. The processors 11 and 21 may also be called controllers, microcontrollers, microprocessors, microcomputers, or the like. The processors 11 and 21 may be implemented by hardware or firmware, software, or a combination thereof. When implementing the present invention using hardware, application specific integrated circuits (ASICs) or digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), FPGAs ( field programmable gate arrays) may be provided in the processors 400a and 400b. Meanwhile, when implementing the present invention using firmware or software, the firmware or software may be configured to include a module, a procedure, or a function for performing the functions or operations of the present invention, and configured to perform the present invention. The firmware or software may be provided in the processors 11 and 21 or stored in the memory 12 and 22 to be driven by the processors 11 and 21.

The processor 11 of the transmission apparatus 10 is predetermined from the processor 11 or a scheduler connected to the processor 11 and has a predetermined encoding and modulation on a signal and / or data to be transmitted to the outside. After performing the transmission to the RF unit 13. For example, the processor 11 converts the data sequence to be transmitted into K layers through demultiplexing, channel encoding, scrambling, and modulation. The coded data string is also called a codeword and is equivalent to a transport block, which is a data block provided by the MAC layer. One transport block (TB) is encoded into one codeword, and each codeword is transmitted to a receiving device in the form of one or more layers. The RF unit 13 may include an oscillator for frequency upconversion. The RF unit 13 may include N _t transmit antennas, where N _t is a positive integer greater than or equal to one.

The signal processing of the receiver 20 is the reverse of the signal processing of the transmitter 10. Under the control of the processor 21, the RF unit 23 of the receiving device 20 receives a radio signal transmitted by the transmitting device 10. The RF unit 23 may include N _r receive antennas, and the RF unit 23 frequency down-converts each of the signals received through the receive antennas to restore the baseband signal. . The RF unit 23 may include an oscillator for frequency downconversion. The processor 21 may decode and demodulate a radio signal received through a reception antenna to restore data originally transmitted by the transmission apparatus 10.

The RF units 13, 23 have one or more antennas. The antenna transmits a signal processed by the RF units 13 and 23 to the outside under the control of the processors 11 and 21, or receives a radio signal from the outside to receive the RF unit 13. , 23). Antennas are also called antenna ports. Each antenna may correspond to one physical antenna or may be configured by a combination of more than one physical antenna elements. The signal transmitted from each antenna can no longer be decomposed by the receiver 20. A reference signal (RS) transmitted in correspondence with the corresponding antenna defines the antenna as viewed from the perspective of the receiver 20, and whether the channel is a single radio channel from one physical antenna or includes the antenna. Regardless of whether it is a composite channel from a plurality of physical antenna elements, the receiver 20 enables channel estimation for the antenna. That is, the antenna is defined such that a channel carrying a symbol on the antenna can be derived from the channel through which another symbol on the same antenna is delivered. In the case of an RF unit supporting a multi-input multi-output (MIMO) function for transmitting and receiving data using a plurality of antennas, two or more antennas may be connected.

In the embodiments of the present invention, the UE operates as the transmitter 10 in the uplink and operates as the receiver 20 in the downlink. In the embodiments of the present invention, the eNB operates as the receiving device 20 in the uplink, and operates as the transmitting device 10 in the downlink. Hereinafter, the processor, the RF unit and the memory provided in the UE will be referred to as a UE processor, the UE RF unit and the UE memory, respectively, and the processor, the RF unit and the memory provided in the eNB will be referred to as an eNB processor, the eNB RF unit and the eNB memory, respectively.

An eNB process according to an embodiment of the present invention may divide the serving cells of the UE into two or more cell groups for the UE. For example, the eNB processor may configure at least one Pcell group including at least one Pcell and at least one Scell group each consisting of one or more Scells. The eNB processor may set one Scell of the corresponding Scell group as an Acell for each Scell group. The eNB processor may control the eNB RF unit to transmit the information on the Scell group and information indicating which of the Scell (s) of the Scell group is the Acell. In addition, the eNB processor may configure PUCCH resource (s) implicitly and / or explicitly in Pcell and Acell. For example, the eNB processor may control the eNB RF unit to set an SR PUCCH resource, an ACK / NACK PUCCH resource, and a CSI PUCCH resource for each of the Pcell and the Acell, and transmit information about the same to the UE. The eNB processor may control the eNB RF unit to transmit UCI configuration information for one or more cells or one or more cell groups among the cells of the UE to the UE. For example, PDCCH, SR PUCCH configuration, periodic / aperiodic CSI reporting configuration, etc. associated with dynamic PUCCH resources may correspond to the UCI configuration information.

 The eNB processor of the present invention may simultaneously receive a plurality of PUCCHs or a plurality of UCIs in a subframe according to any one of embodiments of the present invention. The eNB processor configured according to any one of the embodiments of the present invention knows which PUCCH or UCI the UE configured according to the embodiment will transmit on which CG and which PUCCH or UCI will be dropped, so that the corresponding uplink signal is transmitted. The eNB RF unit may be controlled to receive on the corresponding cell in the corresponding CG. The eNB processor may not expect reception for the PUCCH or UCI dropped by the UE.

The UE processor of the present invention may control the UE RF unit to receive the aforementioned cell group information, Acell information for the cell group, PUCCH resource information, and / or UCI configuration information.

The UE processor of the present invention may configure at least one cell group consisting of a Pcell and zero or more Scells and a cell group consisting of one or more Scells that do not belong to a cell group in which the Pcell is located. The UE processor may set one of the Scell (s) of the cell group consisting of only the Scell (s) as a cell for PUCCH transmission (ie, an Acell). The UE processor may configure cell group (s) and Acell based on cell group information and Acell information.

The UE processor determines whether transmission of a plurality of uplink channels (PUCCHs, PUSCHs, or PUCCHs and PUSCHs) or a plurality of UCIs is required in a subframe based on the PUCCH resource information, UL grant and / or UCI configuration information, and the like. You can judge. The UE processor of the present invention may simultaneously transmit a plurality of PUCCHs or a plurality of UCIs in a subframe according to one of the embodiments of the present invention.

In addition, the eNB processor of the present invention may control the eNB RF unit to transmit / receive a signal according to HARQ timing according to any one of the embodiments of the present invention.

The UE processor of the present invention may control the UE RF unit to transmit / receive a signal according to HARQ timing according to any one of the embodiments of the present invention.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable those skilled in the art to implement and practice the invention. Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Embodiments of the present invention may be used in a base station or user equipment or other equipment in a wireless communication system.

Claims (12)

1. In transmitting a UL signal by a user equipment configured with a plurality of cell groups,

   Receiving UCI transmission information for a plurality of uplink control information (UCI) configured to be transmitted in subframe n through at least one of the plurality of cell groups; And

   On the basis of the UCI transmission information, in the subframe n, comprising transmitting a first UCI of at least the highest priority and a second higher priority of the next plurality of UCI,

   When both the first UCI and the second UCI are configured in a first cell group, the first UCI is transmitted on the first cell group and the second UCI is transmitted on a second cell group other than the first cell group. felled,

   Uplink signal transmission method.
2. According to claim 1,

   One of the first cell group and the second cell group is a primary cell group having a primary cell, and the second cell group is one or more secondary cells that do not belong to the primary cell group without the primary cell. A group of secondary cells,

   Uplink signal transmission method.
3. The method of claim 2,

   Receiving information indicating a special secondary cell for transmitting a physical uplink control channel (PUCCH) among the one or more secondary cells belonging to the primary cell group;

   Uplink signal transmission method.
4. According to claim 1,

   The first UCI and the second UCI is not allowed to transmit simultaneously on a single physical uplink channel,

   Uplink transmission method.
5. According to claim 1,

   If there is a third UCI having a lower priority than the first UCI and the second UCI set in the first cell group or the second cell group in the subframe n, dropping transmission of the third UCI Including more,

   Uplink transmission method.
6. In transmitting a UL signal by a user equipment configured with a plurality of cell groups,

   A radio frequency (RF) unit, and

   A processor configured to control the RF unit, the processor comprising:

   Control the RF unit to receive UCI transmission information for a plurality of uplink control information (UCI) configured to be transmitted in subframe n through at least one of the plurality of cell groups;

   On the basis of the UCI transmission information, in the subframe n, the RF unit is controlled to transmit a first UCI of at least the highest priority and a second UCI of the next higher priority among the plurality of UCI,

   When both the first UCI and the second UCI are configured in a first cell group, the first UCI is transmitted on the first cell group and the second UCI is transmitted on a second cell group other than the first cell group. felled,

   User device.
7. The method of claim 6,

   One of the first cell group and the second cell group is a primary cell group having a primary cell, and the second cell group is one or more secondary cells that do not belong to the primary cell group without the primary cell. A group of secondary cells,

   User device.
8. The method of claim 7, wherein

   Receiving information indicating a special secondary cell for transmitting a physical uplink control channel (PUCCH) among the one or more secondary cells belonging to the primary cell group;

   User device.
9. The method of claim 6,

   The first UCI and the second UCI is not allowed to transmit simultaneously on a single physical uplink channel,

   User device.
10. The method of claim 6,

    If there is a third UCI having a lower priority than the first UCI and the second UCI set in the first cell group or the second cell group in the subframe n, dropping transmission of the third UCI Including more,

    User device.
11. When the base station receives the uplink signal from the user equipment configured with a plurality of cell groups,

    Transmitting UCI transmission information for a plurality of uplink control information (UCI) configured to be transmitted in subframe n through at least one of the plurality of cell groups; And

    Based on the UCI transmission information, in the subframe n, receiving a first UCI of at least a highest priority and a second UCI of a next higher priority among the plurality of UCIs,

    When both the first UCI and the second UCI are configured in a first cell group, the first UCI is received on the first cell group and the second UCI is received on a second cell group other than the first cell group. felled,

    Uplink signal receiving method.
12. When the base station receives the uplink signal from the user equipment configured with a plurality of cell groups,

    A radio frequency (RF) unit, and

    A processor configured to control the RF unit, the processor comprising:

    Control the RF unit to transmit UCI transmission information for a plurality of uplink control information (UCI) configured to be transmitted in subframe n through at least one of the plurality of cell groups;

    On the basis of the UCI transmission information, in the subframe n, the RF unit is controlled to receive a first UCI of at least the highest priority and a second UCI of the next higher priority among the plurality of UCI,

    When both the first UCI and the second UCI are configured in a first cell group, the first UCI is received on the first cell group and the second UCI is received on a second cell group other than the first cell group. felled,

    Base station.

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